139,289 results on '"Alvarado, A."'
Search Results
2. Inclusive Electron Scattering in the Resonance Region off a Hydrogen Target with CLAS12
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Klimenko, V., Carman, D. S., Gothe, R. W., Joo, K., Markov, N., Mokeev, V. I., Niculescu, G., Achenbach, P., Alvarado, J. S., Armstrong, W., Atac, H., Avakian, H., Baashen, L., Baltzell, N. A., Barion, L., Bashkanov, M., Battaglieri, M., Benmokhtar, F., Bianconi, A., Biselli, A. S., Boiarinov, S., Bossu, F., Brinkmann, K. -Th., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Bueltmann, S., Capobianco, R., Carvajal, J., Celentano, A., Chatagnon, P., Ciullo, G., Angelo, A. D, Dashyan, N., Defurne, M., De Vita, R., Deur, A., Diehl, S., Dilks, C., Djalali, C., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fegan, S., Fernando, I. P., Filippi, A., Gavalian, G., Gilfoyle, G. P., Glazier, D. I., Hafidi, K., Hakobyan, H., Hattawy, M., Hauenstein, F., Hayward, T. B., Heddle, D., Blin, A. N. Hiller, Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jiang, H., Jo, H. S., Joosten, S., Kageya, T., Keller, D., Kim, A., Kim, W., Klest, H. T., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lanza, L., Lee, S., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., Martiryan, D., Mascagna, V., Matamoris, D., McKinnon, B., Mineeva, T., Mirazita, M., Camacho, C. Munoz, Turonski, P. Nadel, Nagorna, T., Neupane, K., Niccolai, S., Osipenko, M., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Paul, S. J., Phelps, W., Pilleux, N., Rafael, S. Polcher, Price, J. W., Prok, Y., Raue, B. A., Richards, J., Ripani, M., Ritman, J., Rossi, P., Rusova, A. A., Salgado, C., Schadmand, S., Schmidt, A., Sharabian, Y. G., Shirokov, E. V., Shrestha, S., Sparveris, N., Spreafico, M., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tan, J. A, Tenorio, M., Trotta, N., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Vittorini, T., Voskanyan, H., Voutier, E., Watts, D. P., Weerasinghe, U., Wei, X., Wood, M. H., Xu, L., Zachariou, N., Zhao, Z. W., Zurek, M., and Shresth, S.
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High Energy Physics - Experiment - Abstract
Inclusive electron scattering cross sections off a hydrogen target at a beam energy of 10.6 GeV have been measured with data collected from the CLAS12 spectrometer at Jefferson Laboratory. These first absolute cross sections from CLAS12 cover a wide kinematic area in invariant mass W of the final state hadrons from the pion threshold up to 2.5 GeV for each bin in virtual photon four-momentum transfer squared $Q^2$ from 2.55 to 10.4~GeV$^2$ owing to the large scattering angle acceptance of the CLAS12 detector. Comparison of the cross sections with the resonant contributions computed from the CLAS results on the nucleon resonance electroexcitation amplitudes has demonstrated a promising opportunity to extend the information on their $Q^2$ evolution up to 10 GeV$^2$. Together these results from CLAS and CLAS12 offer good prospects for probing the nucleon parton distributions at large fractional parton momenta $x$ for $W$ < 2.5 GeV, while covering the range of distances where the transition from the strongly coupled to the perturbative regimes is expected.
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- 2025
3. Interleaved bond and magnetic frustration in triangular lattice $Ln$Cd$_3$P$_3$
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Alvarado, S. J. Gomez, Chamorro, J. R., Jackson, A. R., Pokharel, G., Gomez, R., Ortiz, B. R., Sarker, Suchismita, Kautzsch, L., Gallington, L. C., Seshadri, R., and Wilson, Stephen D.
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Condensed Matter - Strongly Correlated Electrons - Abstract
We report the presence of frustrated bond order in the form of short-range charge correlations in the triangular lattice antiferromagnetic compounds $Ln$Cd$_3$P$_3$ ($Ln$ = La, Ce, Pr, and Nd). These compounds feature two-dimensional planes of trigonal-planar CdP$_3$ units that separate tetrahedral CdP$_4$ layers; collectively, these sandwich edge-sharing triangular lattice planes of $Ln$P$_6$ octahedra. Diffuse X-ray scattering data reveal an underlying bond instability within the unique CdP$_3$ units that breaks rotational symmetry along one Cd$-$P bond direction, with long-range ordering being frustrated via emergent kagome-ice bond correlations. Our results establish $Ln$Cd$_3$P$_3$ as a rare class of materials where frustrated magnetism across a tunable rare-earth triangular network is embedded within a dopable semiconductor with a frustrated bond order instability., Comment: 11 pages, 5 figures
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- 2025
4. Characterization of Chromium Impurities in $\beta$-Ga$_2$O$_3$
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Turiansky, Mark E., Mu, Sai, Razinkovas, Lukas, Parto, Kamyar, Patel, Sahil D., Doan, Sean, Pokharel, Ganesh, Alvarado, Steven J. Gomez, Wilson, Stephen D., Moody, Galan, and Van de Walle, Chris G.
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Condensed Matter - Materials Science - Abstract
Chromium is a common transition-metal impurity that is easily incorporated during crystal growth. It is perhaps best known for giving rise to the 694.3 nm (1.786 eV) emission in Cr-doped Al$_2$O$_3$, exploited in ruby lasers. Chromium has also been found in monoclinic gallium oxide, a wide-bandgap semiconductor being pursued for power electronics. In this work, we thoroughly characterize the behavior of Cr in Ga$_2$O$_3$ through theoretical and experimental techniques. $\beta$-Ga$_2$O$_3$ samples are grown with the floating zone method and show evidence of a sharp photoluminescence signal, reminiscent of ruby. We calculate the energetics of formation of Cr from first principles, demonstrating that Cr preferentially incorporates as a neutral impurity on the octahedral site. Cr possesses a quartet ground-state spin and has an internal transition with a zero-phonon line near 1.8 eV. By comparing the calculated and experimentally measured luminescence lineshape function, we elucidate the role of coupling to phonons and uncover features beyond the Franck-Condon approximation. The combination of strong emission with a small Huang-Rhys factor of 0.05 and a technologically relevant host material render Cr in Ga$_2$O$_3$ attractive as a quantum defect.
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- 2024
5. Symbolic regression for precision LHC physics
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Morales-Alvarado, Manuel, Conde, Daniel, Bendavid, Josh, Sanz, Veronica, and Ubiali, Maria
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High Energy Physics - Phenomenology - Abstract
We study the potential of symbolic regression (SR) to derive compact and precise analytic expressions that can improve the accuracy and simplicity of phenomenological analyses at the Large Hadron Collider (LHC). As a benchmark, we apply SR to equation recovery in quantum electrodynamics (QED), where established analytical results from quantum field theory provide a reliable framework for evaluation. This benchmark serves to validate the performance and reliability of SR before extending its application to structure functions in the Drell-Yan process mediated by virtual photons, which lack analytic representations from first principles. By combining the simplicity of analytic expressions with the predictive power of machine learning techniques, SR offers a useful tool for facilitating phenomenological analyses in high energy physics., Comment: 7 pages, 7 figures, 3 tables. Accepted for the Machine Learning and the Physical Sciences Workshop NeurIPS 2024
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- 2024
6. Turbo Receiver Design with Joint Detection and Demapping for Coded Differential BPSK in Bursty Impulsive Noise Channels
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Chen, Chin-Hung, Karanov, Boris, van Houtom, Wim, Wu, Yan, and Alvarado, Alex
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Computer Science - Information Theory ,Electrical Engineering and Systems Science - Signal Processing - Abstract
It has been recognized that the impulsive noise (IN) generated by power devices poses significant challenges to wireless receivers in practice. In this paper, we assess the achievable information rate (AIR) and the performance of practical turbo receiver designs for a well-established Markov-Middleton IN model. We utilize a commonly used commercial transmission setup consisting of a convolutional encoder, bit-level interleaver, and a differential binary phase-shift keying (DBPSK) symbol mapper. Firstly, we conduct a comprehensive assessment of the AIRs of the underlying channel model using DBPSK transmitted symbols across various channel conditions. Additionally, we introduce two robust turbo-like receiver designs. The first design features a separate IN detector and a turbo-demapper-decoder. The second design employs a joint approach, where the extrinsic information of both the detector and demapper is simultaneously updated, forming a turbo-detector-demapper-decoder structure. We show that the joint design consistently outperforms the separate design across all channel conditions, particularly in low AIR situations. However, the maximum performance gain for the channel conditions considered in this paper is merely 0.2 dB, and the joint system incurs significantly greater computational complexity, especially for a high number of turbo iterations. The performance of the two proposed turbo receiver designs is demonstrated to be close to the estimated AIR, with a performance gap dependent on the channel parameters., Comment: 12 pages, 13 figures
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- 2024
7. Modified Baum-Welch Algorithm for Joint Blind Channel Estimation and Turbo Equalization
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Chen, Chin-Hung, Karanov, Boris, Nikoloska, Ivana, van Houtum, Wim, Wu, Yan, and Alvarado, Alex
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Electrical Engineering and Systems Science - Signal Processing ,Computer Science - Information Theory - Abstract
Blind estimation of intersymbol interference channels based on the Baum-Welch (BW) algorithm, a specific implementation of the expectation-maximization (EM) algorithm for training hidden Markov models, is robust and does not require labeled data. However, it is known for its extensive computation cost, slow convergence, and frequently converges to a local maximum. In this paper, we modified the trellis structure of the BW algorithm by associating the channel parameters with two consecutive states. This modification enables us to reduce the number of required states by half while maintaining the same performance. Moreover, to improve the convergence rate and the estimation performance, we construct a joint turbo-BW-equalization system by exploiting the extrinsic information produced by the turbo decoder to refine the BW-based estimator at each EM iteration. Our experiments demonstrate that the joint system achieves convergence in 10 EM iterations, which is 8 iterations less than a separate system design for a signal-to-noise ratio (SNR) of 4dB. Additionally, the joint system provides improved estimation accuracy with a mean square error (MSE) of $10^{-4}$ for an SNR of 6dB. We also identify scenarios where a joint design is not preferable, especially when the channel is noisy (e.g., SNR=2dB) and the decoder cannot provide reliable extrinsic information for a BW-based estimator., Comment: Accepted paper for 14th International ITG Conference on Systems, Communications and Coding (SCC)
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- 2024
8. BimArt: A Unified Approach for the Synthesis of 3D Bimanual Interaction with Articulated Objects
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Zhang, Wanyue, Dabral, Rishabh, Golyanik, Vladislav, Choutas, Vasileios, Alvarado, Eduardo, Beeler, Thabo, Habermann, Marc, and Theobalt, Christian
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Computer Science - Computer Vision and Pattern Recognition ,Computer Science - Graphics ,Computer Science - Robotics - Abstract
We present BimArt, a novel generative approach for synthesizing 3D bimanual hand interactions with articulated objects. Unlike prior works, we do not rely on a reference grasp, a coarse hand trajectory, or separate modes for grasping and articulating. To achieve this, we first generate distance-based contact maps conditioned on the object trajectory with an articulation-aware feature representation, revealing rich bimanual patterns for manipulation. The learned contact prior is then used to guide our hand motion generator, producing diverse and realistic bimanual motions for object movement and articulation. Our work offers key insights into feature representation and contact prior for articulated objects, demonstrating their effectiveness in taming the complex, high-dimensional space of bimanual hand-object interactions. Through comprehensive quantitative experiments, we demonstrate a clear step towards simplified and high-quality hand-object animations that excel over the state-of-the-art in motion quality and diversity.
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- 2024
9. Sensitivity of Double Deeply Virtual Compton Scattering observables to GPDs
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Alvarado, J. S., Hoballah, M., and Voutier, E.
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Nuclear Experiment ,High Energy Physics - Phenomenology - Abstract
Generalized Parton Distributions (GPDs) are multidimensonal structure functions that encode the information about the internal structure of hadrons. Using privileged channels such as Deeply Virtual Compton Scattering (DVCS) or Timelike Compton Scattering (TCS), it is possible to make direct measurements at points where the momentum fraction of the parton equals the respective scaling variable. Double Deeply Virtual Compton Scattering (DDVCS) is a not yet measured and promising channel for GPD studies as it allows to perform more general measurements at independent momentum fraction and scaling variable values. GPDs are extracted from Compton Form Factors which arise naturally in experimental observables from different combinations of beam and target configurations. In the context of the Continuous Electron Beam Accelerator Facility (CEBAF) and the Electron Ion Collider (EIC), we report the results of an exhaustive study of the DDVCS observables from polarized electron and positron beams directed to a polarized proton target. The study focuses on the sensitivity of the observables to the parton helicity conserving proton GPDs, particularly the consequences for GPDs measurements via DDVCS at CEBAF and EIC based on the VGG and GK19 model predictions., Comment: 5 pages, 3 figures, conference proceedings for the 31st International Workshop on Deep Inelastic Scattering (DIS2024)
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- 2024
10. Understanding the Learning Experiences of Low-Income Midwest Rural Latinx Youth during COVID-19: A Culturally Responsive Approach
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Diana Cedeño, Pingping Fu, and Rosalba Alvarado
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While research acknowledged the challenges faced by students during the COVID-19 pandemic, a critical gap existed in understanding the specific experiences of low-income Latinx youth. This study explored how these students navigated the transition to remote learning through a culturally responsive critical literacy program that incorporated their cultural backgrounds and lived experiences into the learning process. Findings from nine rural Latinx youth revealed a lack of motivation and anxieties surrounding both the remote learning format and the economic hardships their families faced due to the pandemic. Despite these challenges, strong community and family support (bridging & bonding) emerged as a crucial factor in fostering resilience. This research underscores the importance of culturally responsive pedagogy (CRP) that validates Latinx culture and knowledge. It argues against standardized curricula, advocating for a re-envisioned CRP that integrates community-driven initiatives and prioritizes language considerations. Implications for practice are provided.
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- 2025
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11. Diverse microbiome functions, limited temporal variation and substantial genomic conservation within sedimentary and granite rock deep underground research laboratories.
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Amano, Yuki, Sachdeva, Rohan, Gittins, Daniel, Anantharaman, Karthik, Lei, Shufei, Valentin-Alvarado, Luis, Diamond, Spencer, Beppu, Hikari, Iwatsuki, Teruki, Mochizuki, Akihito, Miyakawa, Kazuya, Ishii, Eiichi, Murakami, Hiroaki, Jaffe, Alexander, Castelle, Cindy, Lavy, Adi, Suzuki, Yohey, and Banfield, Jillian
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Granite ,Groundwater ,Metagenomics microbiome ,Sedimentary rocks ,Stability ,Underground research laboratory - Abstract
BACKGROUND: Underground research laboratories (URLs) provide a window on the deep biosphere and enable investigation of potential microbial impacts on nuclear waste, CO2 and H2 stored in the subsurface. We carried out the first multi-year study of groundwater microbiomes sampled from defined intervals between 140 and 400 m below the surface of the Horonobe and Mizunami URLs, Japan. RESULTS: We reconstructed draft genomes for > 90% of all organisms detected over a four year period. The Horonobe and Mizunami microbiomes are dissimilar, likely because the Mizunami URL is hosted in granitic rock and the Horonobe URL in sedimentary rock. Despite this, hydrogen metabolism, rubisco-based CO2 fixation, reduction of nitrogen compounds and sulfate reduction are well represented functions in microbiomes from both URLs, although methane metabolism is more prevalent at the organic- and CO2-rich Horonobe URL. High fluid flow zones and proximity to subsurface tunnels select for candidate phyla radiation bacteria in the Mizunami URL. We detected near-identical genotypes for approximately one third of all genomically defined organisms at multiple depths within the Horonobe URL. This cannot be explained by inactivity, as in situ growth was detected for some bacteria, albeit at slow rates. Given the current low hydraulic conductivity and groundwater compositional heterogeneity, ongoing inter-site strain dispersal seems unlikely. Alternatively, the Horonobe URL microbiome homogeneity may be explained by higher groundwater mobility during the last glacial period. Genotypically-defined species closely related to those detected in the URLs were identified in three other subsurface environments in the USA. Thus, dispersal rates between widely separated underground sites may be fast enough relative to mutation rates to have precluded substantial divergence in species composition. Species overlaps between subsurface locations on different continents constrain expectations regarding the scale of global subsurface biodiversity. CONCLUSIONS: Our analyses reveal microbiome stability in the sedimentary rocks and surprising microbial community compositional and genotypic overlap over sites separated by hundreds of meters of rock, potentially explained by dispersal via slow groundwater flow or during a prior hydrological regime. Overall, microbiome and geochemical stability over the study period has important implications for underground storage applications.
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- 2024
12. Early-life obesogenic environment integrates immunometabolic and epigenetic signatures governing neuroinflammation.
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Ontiveros-Ángel, Perla, Vega-Torres, Julio, Simon, Timothy, Williams, Vivianna, Inostroza-Nives, Yaritza, Alvarado-Crespo, Nashareth, Gonzalez, Yarimar, Pompolius, Marjory, Katzka, William, Lou, John, Sharafeddin, Fransua, De la Peña, Ike, Dong, Tien, Gupta, Arpana, Viet, Chi, Febo, Marcelo, Obenaus, Andre, Nair, Aarti, and Figueroa, Johnny
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Adolescence ,Anxiety ,FKBP5 ,Microbiome ,Microglia ,NODDI ,Neuroinflammation ,Obesity - Abstract
Childhood overweight/obesity is associated with stress-related psychopathology, yet the pathways connecting childhood obesity to stress susceptibility are poorly understood. We employed a systems biology approach with 62 adolescent Lewis rats fed a Western-like high-saturated fat diet (WD, 41% kcal from fat) or a control diet (CD, 13% kcal from fat). A subset of rats underwent a 31-day model of predator exposures and social instability (PSS). Effects were assessed using behavioral tests, DTI (diffusion tensor imaging), NODDI (neurite orientation dispersion and density imaging), 16S rRNA gene sequencing for gut microbiome profiling, hippocampal microglia analysis, and targeted gene methylation. Parallel experiments on human microglia cells (HMC3) examined how palmitic acid influences cortisol-related inflammatory responses. Rats exposed to WD and PSS exhibited deficits in sociability, increased fear/anxiety-like behaviors, food consumption, and body weight. WD/PSS altered hippocampal microstructure (subiculum, CA1, dentate gyrus), and microbiome analysis showed a reduced abundance of members of the phylum Firmicutes. WD/PSS synergistically promoted neuroinflammatory changes in hippocampal microglia, linked with microbiome shifts and altered Fkbp5 expression/methylation. In HMC3, palmitate disrupted cortisol responses, affecting morphology, phagocytic markers, and cytokine release, partially mediated by FKBP5. This study identifies gene-environment interactions that influence microglia biology and may contribute to the connection between childhood obesity and stress-related psychopathology later in life.
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- 2024
13. Equidistribution of Hecke Orbits on the Picard group of definite Shimura curves
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Alvarado, Matias and Pérez-Piña, Patricio
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Mathematics - Number Theory ,11G09, 11G18, 11F52 - Abstract
We prove an equidistribution result about Hecke orbits on the Picard group of Shimura curves coming from definite quaternion algebras over function fields. In particular, we show the equidistribution of Hecke orbits of supersingular Drinfeld modules of rank 2. Our approach is via the automorphic method, using bounds for coefficients of cuspidal automorphic forms of Drinfeld type as the main tool.
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- 2024
14. A canonical Ramsey theorem for even cycles in random graphs
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Alvarado, José D., Kohayakawa, Y., Morris, Patrick, and Mota, Guilherme O.
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Mathematics - Combinatorics - Abstract
The celebrated canonical Ramsey theorem of Erd\H{o}s and Rado implies that for $2\leq k\in \mathbb{N}$, any colouring of the edges of $K_n$ with $n$ sufficiently large gives a copy of $C_{2k}$ which has one of three canonical colour patterns: monochromatic, rainbow or lexicographic. In this paper we show that if $p=\omega(n^{-1+1/(2k-1)}\log n)$, then ${\mathbf{G}}(n,p)$ will asymptotically almost surely also have the property that any colouring of its edges induces canonical copies of $C_{2k}$. This determines the threshold for the canonical Ramsey property with respect to even cycles, up to a $\log$ factor., Comment: 24 pages + 4 pages of appendix, 1 figure
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- 2024
15. Stability frontiers in the AM$_6$X$_6$ kagome metals; The LnNb$_6$Sn$_6$ (Ln:Ce-Lu,Y) family and density-wave transition in LuNb$_6$Sn$_6$
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Ortiz, Brenden R., Meier, William R., Pokharel, Ganesh, Chamorro, Juan, Yang, Fazhi, Mozaffari, Shirin, Thaler, Alex, Alvarado, Steven J. Gomez, Zhang, Heda, Parker, David S., Samolyuk, German D., Paddison, Joseph A. M., Yan, Jiaqiang, Ye, Feng, Sarker, Suchismita, Wilson, Stephen D., Miao, Hu, Mandrus, David, and McGuire, Michael A.
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Condensed Matter - Strongly Correlated Electrons ,Condensed Matter - Materials Science ,Condensed Matter - Other Condensed Matter - Abstract
The kagome motif is a versatile platform for condensed matter physics, hosting rich interactions between magnetic, electronic, and structural degrees of freedom. In recent years, the discovery of a charge density wave (CDW) in the AV$_3$Sb$_5$ superconductors and structurally-derived bond density waves in FeGe and ScV$_6$Sn$_6$ have stoked the search for new kagome platforms broadly exhibiting density wave (DW) transitions. In this work, we evaluate the known AM$_6$X$_6$ chemistries and construct a stability diagram that summarizes the structural relationships between the $\approx$125 member family. Subsequently we introduce our discovery of the broader LnNb$_6$Sn$_6$ (Ln:Ce-Nd,Sm,Gd-Tm,Lu,Y) family of kagome metals and an analogous DW transition in LuNb$_6$Sn$_6$. Our X-ray scattering measurements clearly indicate a (1/3, 1/3, 1/3) ordering wave vector ($\sqrt{3}\times\sqrt{3}\times3$ superlattice) and diffuse scattering on half-integer $L$-planes. Our analysis of the structural data supports the ``rattling mode'' DW model proposed for ScV$_6$Sn$_6$ and paints a detailed picture of the steric interactions between the rare-earth filler element and the host Nb-Sn kagome scaffolding. We also provide a broad survey of the magnetic properties within the HfFe$_6$Ge$_6$-type LnNb$_6$Sn$_6$ members, revealing a number of complex antiferromagnetic and metamagnetic transitions throughout the family. This work integrates our new LnNb$_6$Sn$_6$ series of compounds into the broader AM$_6$X$_6$ family, providing new material platforms and forging a new route forward at the frontier of kagome metal research.
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- 2024
16. Microscale velocity-dependent unbinding generates a macroscale performance-efficiency tradeoff in actomyosin systems
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McGrath, Jake, Kent, Brian, Johnson, Colin, and Alvarado, José
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Physics - Biological Physics - Abstract
Myosin motors are fundamental biological actuators, powering diverse mechanical tasks in eukaryotic cells via ATP hydrolysis. Recent work revealed that myosin's velocity-dependent detachment rate can bridge actomyosin dynamics to macroscale Hill muscle predictions. However, the influence of this microscale unbinding, which we characterize by a dimensionless parameter $\alpha$, on macroscale energetic flows-such as power consumption, output and efficiency-remains elusive. Here we develop an analytical model of myosin dynamics that relates unbinding rates $\alpha$ to energetics. Our model agrees with published in-vivo muscle data and, furthermore, uncovers a performance-efficiency tradeoff governed by $\alpha$. To experimentally validate the tradeoff, we build HillBot, a robophysical model of Hill's muscle that mimics nonlinearity. Through HillBot, we decouple $\alpha$'s concurrent effect on performance and efficiency, demonstrating that nonlinearity drives efficiency. We compile 136 published measurements of $\alpha$ in muscle and myoblasts to reveal a distribution centered at $\alpha^* = 3.85 \pm 2.32$. Synthesizing data from our model and HillBot, we quantitatively show that $\alpha^*$ corresponds to a class of generalist actuators that are both relatively powerful and efficient, suggesting that the performance-efficiency tradeoff underpins the prevalence of $\alpha^*$ in nature. We leverage these insights and propose a nonlinear variable-impedance protocol to shift along a performance-efficiency axis in robotic applications., Comment: 23 pages, 6 figures. PDF of supplemental information available in zip download
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- 2024
17. Origins of Super Jupiters: TOI-2145b Has a Moderately Eccentric and Nearly Aligned Orbit
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Dong, Jiayin, Chontos, Ashley, Zhou, George, Stefansson, Gudmundur, Wang, Songhu, Huang, Chelsea X., Gupta, Arvind F., Halverson, Samuel, Kanodia, Shubham, Luhn, Jacob K., Mahadevan, Suvrath, Monson, Andrew, Alvarado-Montes, Jaime A., Ninan, Joe P., Robertson, Paul, Roy, Arpita, Schwab, Christian, and Wright, Jason T.
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Astrophysics - Earth and Planetary Astrophysics - Abstract
Super Jupiters are giant planets with several Jupiter masses. It remains an open question whether these planets originate with such high masses or grow through collisions. Previous work demonstrates that warm super Jupiters tend to have more eccentric orbits compared to regular-mass warm Jupiters. This correlation between mass and eccentricity may indicate that planet-planet interactions significantly influence the warm giant planet demographics. Here we conducted a detailed characterization of a warm super Jupiter, TOI-2145b. This analysis utilized previous observations from TESS and Keck/HIRES, enhanced by new Rossiter-McLaughlin effect data from the NEID spectrometer on the 3.5 m WIYN Telescope. TOI-2145b is a $5.68^{+0.37}_{-0.34} M_{\rm Jup}$ planet on a moderate eccentricity ($e = 0.214^{+0.014}_{-0.014}$), 10.26-day orbit, orbiting an evolved A-star. We constrain the projected stellar obliquity to be $\lambda = 6.8^{+2.9}_{-3.8}$$^\circ$ from two NEID observations. Our $N$-body simulations suggest that the formation of super Jupiter TOI-2145b could involve either of two scenarios: a high initial mass or growth via collisions. On a population level, however, the collision scenario can better describe the mass-eccentricity distribution of observed warm Jupiters., Comment: 13 pages, 5 figures, 1 table, AJ accepted
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- 2024
18. Borel regularity is equivalent to Lusin's theorem and the existence of Borel representatives
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Alvarado, Ryan, Górka, Przemysław, and Słabuszewski, Artur
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Mathematics - Functional Analysis - Abstract
In this article, we characterize both Lusin's theorem and the existence of Borel representatives via the regularity properties of the measure in general topological measure spaces. As a corollary, we prove that Borel regularity of the measure is both a necessary and sufficient condition for these results to hold true in metric measure spaces.
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- 2024
19. The Empirical Watershed Wavelet
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Hurat, Basile, Alvarado, Zariluz, and Gilles, Jerome
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Mathematics - Spectral Theory ,Computer Science - Computer Vision and Pattern Recognition ,Mathematics - Functional Analysis ,42C40 ,G.0 - Abstract
The empirical wavelet transform is an adaptive multiresolution analysis tool based on the idea of building filters on a data-driven partition of the Fourier domain. However, existing 2D extensions are constrained by the shape of the detected partitioning. In this paper, we provide theoretical results that permits us to build 2D empirical wavelet filters based on an arbitrary partitioning of the frequency domain. We also propose an algorithm to detect such partitioning from an image spectrum by combining a scale-space representation to estimate the position of dominant harmonic modes and a watershed transform to find the boundaries of the different supports making the expected partition. This whole process allows us to define the empirical watershed wavelet transform. We illustrate the effectiveness and the advantages of such adaptive transform, first visually on toy images, and next on both unsupervised texture segmentation and image deconvolution applications.
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- 2024
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20. On the Design and Performance of Machine Learning Based Error Correcting Decoders
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Yuan, Yuncheng, Scheepers, Péter, Tasiou, Lydia, Gültekin, Yunus Can, Corradi, Federico, and Alvarado, Alex
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Electrical Engineering and Systems Science - Signal Processing ,Computer Science - Machine Learning - Abstract
This paper analyzes the design and competitiveness of four neural network (NN) architectures recently proposed as decoders for forward error correction (FEC) codes. We first consider the so-called single-label neural network (SLNN) and the multi-label neural network (MLNN) decoders which have been reported to achieve near maximum likelihood (ML) performance. Here, we show analytically that SLNN and MLNN decoders can always achieve ML performance, regardless of the code dimensions -- although at the cost of computational complexity -- and no training is in fact required. We then turn our attention to two transformer-based decoders: the error correction code transformer (ECCT) and the cross-attention message passing transformer (CrossMPT). We compare their performance against traditional decoders, and show that ordered statistics decoding outperforms these transformer-based decoders. The results in this paper cast serious doubts on the application of NN-based FEC decoders in the short and medium block length regime., Comment: 6 pages, 4 figures, submitted for possible presentation in a conference (v2: Pre-FEC BER curves are corrected)
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- 2024
21. Optimizing Attention with Mirror Descent: Generalized Max-Margin Token Selection
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Julistiono, Aaron Alvarado Kristanto, Tarzanagh, Davoud Ataee, and Azizan, Navid
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Computer Science - Machine Learning ,Computer Science - Artificial Intelligence ,Computer Science - Computation and Language - Abstract
Attention mechanisms have revolutionized several domains of artificial intelligence, such as natural language processing and computer vision, by enabling models to selectively focus on relevant parts of the input data. While recent work has characterized the optimization dynamics of gradient descent (GD) in attention-based models and the structural properties of its preferred solutions, less is known about more general optimization algorithms such as mirror descent (MD). In this paper, we investigate the convergence properties and implicit biases of a family of MD algorithms tailored for softmax attention mechanisms, with the potential function chosen as the $p$-th power of the $\ell_p$-norm. Specifically, we show that these algorithms converge in direction to a generalized hard-margin SVM with an $\ell_p$-norm objective when applied to a classification problem using a softmax attention model. Notably, our theoretical results reveal that the convergence rate is comparable to that of traditional GD in simpler models, despite the highly nonlinear and nonconvex nature of the present problem. Additionally, we delve into the joint optimization dynamics of the key-query matrix and the decoder, establishing conditions under which this complex joint optimization converges to their respective hard-margin SVM solutions. Lastly, our numerical experiments on real data demonstrate that MD algorithms improve generalization over standard GD and excel in optimal token selection.
- Published
- 2024
22. Gaia-4b and 5b: Radial Velocity Confirmation of Gaia Astrometric Orbital Solutions Reveal a Massive Planet and a Brown Dwarf Orbiting Low-mass Stars
- Author
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Stefansson, Gudmundur, Mahadevan, Suvrath, Winn, Joshua, Marcussen, Marcus, Kanodia, Shubham, Albrecht, Simon, Fitzmaurice, Evan, Mikulskitye, One, Cañas, Caleb, Espinoza-Retamal, Juan Ignacio, Zwart, Yiri, Krolikowski, Daniel, Hotnisky, Andrew, Robertson, Paul, Alvarado-Montes, Jaime A., Bender, Chad, Blake, Cullen, Callingham, Joe, Cochran, William, Delamer, Megan, Diddams, Scott, Dong, Jiayin, Fernandes, Rachel, Giovanazzi, Mark, Halverson, Samuel, Libby-Roberts, Jessica, Logsdon, Sarah E, McElwain, Michael, Ninan, Joe, Rajagopal, Jayadev, Reji, Varghese, Roy, Arpita, Schwab, Christian, and Wright, Jason
- Subjects
Astrophysics - Earth and Planetary Astrophysics ,Astrophysics - Instrumentation and Methods for Astrophysics ,Astrophysics - Solar and Stellar Astrophysics - Abstract
Gaia astrometry of nearby stars is precise enough to detect the tiny displacements induced by substellar companions, but radial velocity data are needed for definitive confirmation. Here we present radial velocity follow-up observations of 28 M and K stars with candidate astrometric substellar companions, which led to the confirmation of two systems, Gaia-4b and Gaia-5b, and the refutation of 21 systems as stellar binaries. Gaia-4b is a massive planet ($M = 11.8 \pm 0.7 \:\mathrm{M_J}$) in a $P = 571.3 \pm 1.4\:\mathrm{day}$ orbit with a projected semi-major axis $a_0=0.312 \pm 0.040\:\mathrm{mas}$ orbiting a $0.644 \pm 0.02 \:\mathrm{M_\odot}$ star. Gaia-5b is a brown dwarf ($M = 20.9 \pm 0.5\:\mathrm{M_J}$) in a $P = 358.58 \pm 0.19\:\mathrm{days}$ eccentric $e=0.6412 \pm 0.0027$ orbit with a projected angular semi-major axis of $a_0 = 0.947 \pm 0.038\:\mathrm{mas}$ around a $0.34 \pm 0.03 \mathrm{M_\odot}$ star. Gaia-4b is one of the first exoplanets discovered via the astrometric technique, and is one of the most massive planets known to orbit a low-mass star., Comment: Submitted to AAS journals. 26 pages, 12 figures, 4 tables
- Published
- 2024
23. Information Reconciliation for Continuous-Variable Quantum Key Distribution Beyond the Devetak-Winter Bound Using Short Blocklength Error Correction Codes
- Author
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Gümüş, Kadir, Frazão, João dos Reis, Albores-Mejia, Aaron, Škorić, Boris, Liga, Gabriele, Gültekin, Yunus Can, Bradley, Thomas, Alvarado, Alex, and Okonkwo, Chigo
- Subjects
Quantum Physics - Abstract
In this paper we introduce a reconciliation protocol with a two-step error correction scheme using a short blocklength low rate code and a long blocklength high rate code. We show that by using this two-step decoding method it is possible to achieve secret key rates beyond the Devetak-Winter bound. We simulate the protocol using short blocklength low-density parity check code, and show that we can obtain reconciliation efficiencies up to 1.5. Using these high reconciliation efficiencies, it is possible double the achievable distances of CV-QKD systems., Comment: Pre-print
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- 2024
24. Measurement of the nucleon spin structure functions for 0.01<$Q^2$<1 GeV$^2$ using CLAS
- Author
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Deur, A., Kuhn, S. E., Ripani, M., Zheng, X., Acar, A. G., Achenbach, P., Adhikari, K. P., Alvarado, J. S., Amaryan, M. J., Armstrong, W. R., Atac, H., Avakian, H., Baashen, L., Baltzell, N. A., Barion, L., Bashkanov, M., Battaglieri, M., Benkel, B., Benmokhtar, F., Bianconi, A., Biselli, A. S., Booth, W. A., ossu, F. B, Bosted, P., Boiarinov, S., Brinkmann, K. Th., Briscoe, W. J., Bueltmann, S., Burkert, V. D., Carman, D. S., Chatagnon, P., Chen, J. P., Ciullo, G., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Diehl, S., Djalali, C., Drozdov, V. A., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Faggert, J. C., Fegan, S., Fersch, R., Filippi, A., Gates, K., Gavalian, G., Gilfoyle, G. P., Gothe, R. W., Guo, L., Hakobyan, H., Hattawy, M., Hauenstein, F., Heddle, D., Hobart, A., Holtrop, M., Ireland, D. G., Isupov, E. L., Jiang, H., Jo, H. S., Joosten, S., Kang, H., Keith, C., Khandaker, M., Kim, W., Klein, F. J., Klimenko, V., Konczykowski, P., Kovacs, K., Kripko, A., Kubarovsky, V., Lanza, L., Lee, S., Lenisa, P., Li, X., Long, E., MacGregor, I. J. D., Marchand, D., Mascagna, V., Matamoros, D., McKinnon, B., Meekins, D., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Munoz-Camacho, C., Nadel-Turonski, P., Nagorna, T., Neupane, K., Niccolai, S., Osipenko, M., Ostrovidov, A. I., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Paul, S. J., Phelps, W., Phillips, S. K., Pierce, J., Pilleux, N., Pokhrel, M., Price, J. W., Prok, Y., Radic, A., Reed, T., Richards, J., Rosner, G., Rossi, P., Rusova, A. A., Salgado, C., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shirokov, E. V., Shrestha, U., Sirca, S., Sparveris, N., Spreafico, M., Stepanyan, S., Strakovsky, I. I., Strauch, S., Sulkosky, V., Tan, J. A., Tenorio, M., Trotta, N., Tyson, R., Ungaro, M., Upton, D. W., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, X., Wood, M. H., Zachariou, N., Zhang, J., and Zurek, M.
- Subjects
Nuclear Experiment - Abstract
The spin structure functions of the proton and the deuteron were measured during the EG4 experiment at Jefferson Lab in 2006. Data were collected for longitudinally polarized electron scattering off longitudinally polarized NH$_3$ and ND$_3$ targets, for $Q^2$ values as small as 0.012 and 0.02 GeV$^2$, respectively, using the CEBAF Large Acceptance Spectrometer (CLAS). This is the archival paper of the EG4 experiment that summaries the previously reported results of the polarized structure functions $g_1$, $A_1F_1$, and their moments $\overline \Gamma_1$, $\overline \gamma_0$, and $\overline I_{TT}$, for both the proton and the deuteron. In addition, we report on new results on the neutron $g_1$ extracted by combining proton and deuteron data and correcting for Fermi smearing, and on the neutron moments $\overline \Gamma_1$, $\overline \gamma_0$, and $\overline I_{TT}$ formed directly from those of the proton and the deuteron. Our data are in good agreement with the Gerasimov-Drell-Hearn sum rule for the proton, deuteron, and neutron. Furthermore, the isovector combination was formed for $g_1$ and the Bjorken integral $\overline \Gamma_1^{p-n}$, and compared to available theoretical predictions. All of our results provide for the first time extensive tests of spin observable predictions from chiral effective field theory ($\chi$EFT) in a $Q^2$ range commensurate with the pion mass. They motivate further improvement in $\chi$EFT calculations from other approaches such as the lattice gauge method., Comment: 33 pages. 26 figures. Data table provided as supplementary material (30 pages latex and csv tables)
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- 2024
25. On Dihedral Group Actions on Riemann Surfaces
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Alvarado-Seguel, Pablo and Reyes-Carocca, Sebastián
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Mathematics - Algebraic Geometry ,30F10 (Primary) 14H37, 14H40, 14H30 (Secondary) - Abstract
This article deals with dihedral group actions on compact Riemann surfaces and the interplay between different geometric data associated to them. First, a bijective correspondence between geometric signatures and analytic representations is obtained. Second, a refinement of a result of Bujalance, Cirre, Gamboa and Gromadzki about signature realization is provided. Finally, we apply our results to isogeny decompositions of Jacobians by Prym varieties and by elliptic curves, extending results of Carocca, Recillas and Rodr\'iguez. In particular, we give a complete classification of Jacobians with dihedral action whose group algebra decomposition induces a decomposition into factors of the same dimension., Comment: 32 pages
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- 2024
26. Cosmic Acceleration from topological considerations III: Lie group
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Alvarado, I. A. Sarmiento, Márquez, Maribel Hernández, and Matos, Tonatiuh
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General Relativity and Quantum Cosmology - Abstract
Recent observations on the large-scale structure of the universe indicate that the cosmological constant cannot be the definitive answer to the nature of dark energy. Therefore, it is a good time to propose alternatives to understand the late-accelerated expansion of the universe. In this work we study the possibility that the acceleration of space-time is due to the topology of the universe. We assume that the topology of the universe is a principal fiber bundle whose base space is our 4-dimensional spacetime and the fiber is an $N$-dimensional Lie group that evolves with time. For the base space we consider a homogeneous and isotropic spacetime, we find that the base space is currently accelerating for $1 < N$ compact semi-simple Lie groups whose scale-factors are equal and for $1 < N$ non-Abelian Lie groups whose scale-factors are different and as long as its structure constants satisfy some conditions. However when we study the evolution of the density parameters these differ from the evolution within the $\Lambda$CDM model, this led us to think in the possibility of use a different group as fiber in order to obtain the right evolution of the density parameters. We conclude that it is possible that the accelerated expansion of the universe is due to consider a different topology of the universe as a principal fiber bundle., Comment: 16 pages, 5 figures
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- 2024
27. Alternative Bell's states and teleportation
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Romero, Juan M., Montoya-Gonzalez, Emiliano, and Velazquez-Alvarado, Oscar
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Quantum Physics - Abstract
Bell's states are among the most useful in quantum computing. These state are an orthonormal base of entagled states with two qubits. We propose alternative bases of entangled states. Some of these states depend on a continuous parameter. We present the quantum circuit and code of these alternative bases. In addition, we study quantum teleportation with these entangled states and present their quantum circuits and codes associated., Comment: 39 pages, 15 figures, minor corrections. Comments welcome
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- 2024
28. Searching for Tidal Orbital Decay in Hot Jupiters
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Alvarado III, Efrain, Bostow, Kate B., Patra, Kishore C., Jacobus, Cooper H., Baer-Way, Raphael A., Jennings, Connor F., Pichay, Neil R., deGraw, Asia A., Vidal, Edgar P., Chander, Vidhi, Altunin, Ivan A., Brendel, Victoria M., Ehrich, Kingsley E., Sunseri, James D., May, Michael B., Punjabi, Druv H., Gendreau-Distler, Eli A., Risin, Sophia, Brink, Thomas G., Zheng, WeiKang, and Filippenko, Alexei V.
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Astrophysics - Earth and Planetary Astrophysics - Abstract
We study transits of several ``hot Jupiter'' systems - including WASP-12 b, WASP-43 b, WASP-103 b, HAT-P-23 b, KELT-16 b, WD 1856+534 b, and WTS-2 b - with the goal of detecting tidal orbital decay and extending the baselines of transit times. We find no evidence of orbital decay in any of the observed systems except for that of the extensively studied WASP-12 b. Although the orbit of WASP-12 b is unequivocally decaying, we find no evidence for acceleration of said orbital decay, with measured $\ddot{P} = (-7 \pm 8) \times 10^{-14} \rm ~s^{-1}$, against the expected acceleration decay of $\ddot{P} \approx -10^{-23} \rm ~s^{-1}$. In the case of WD 1856+534 b, there is a tentative detection of orbital growth with $\dot{P} = (5.0 \pm 1.5) \times 10^{-10}$. While statistically significant, we err on the side of caution and wait for longer follow-up observations to consider the measured $\dot{P}$ real. For most systems, we provide a 95\%-confidence lower limit on the tidal quality factor, $Q_\star'$. The possibility of detecting orbital decay in hot Jupiters via long-term radial velocity (RV) measurements is also explored. We find that $\sim 1 \rm ~m~s^{-1}$ precision in RVs will be required to detect orbital decay of WASP-12 b with only 3 yr of observations. Currently available RV measurements and precision are unable to detect orbital decay in any of the systems studied here., Comment: 14 pages, 11 figures; Accepted in MNRAS on 2024 August 30. Received 2024 August 29; in original form 2024 February 13
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- 2024
29. Locally recoverable algebro-geometric codes with multiple recovery sets from projective bundles
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Aguilar, Konrad, Álvarez, Angelynn, Ardila, René, Ocal, Pablo S., Avila, Cristian Rodriguez, and Várilly-Alvarado, Anthony
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Computer Science - Information Theory ,Mathematics - Algebraic Geometry ,94B27, 14G50, 11G25 - Abstract
A code is locally recoverable when each symbol in one of its code words can be reconstructed as a function of $r$ other symbols. We use bundles of projective spaces over a line to construct locally recoverable codes with availability; that is, evaluation codes where each code word symbol can be reconstructed from several disjoint sets of other symbols. The simplest case, where the code's underlying variety is a plane, exhibits noteworthy properties: When $r = 1$, $2$, $3$, they are optimal; when $r \geq 4$, they are optimal with probability approaching $1$ as the alphabet size grows. Additionally, their information rate is close to the theoretical limit. In higher dimensions, our codes form a family of asymptotically good codes., Comment: 25 pages, 3 figures
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- 2024
30. Searching for GEMS: TOI-5688 A b, a low-density giant orbiting a high-metallicity early M-dwarf
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Reji, Varghese, Kanodia, Shubham, Ninan, Joe, Cañas, Caleb I., Libby-Roberts, Jessica, Lin, Andrea S. J., Gupta, Arvind F, Sewaby, Tera N., Larsen, Alexander, Kobulnicky, Henry A., Choi, Philip I., Evans, Nez, Santomenna, Sage, Winnick, Isabelle, Yu, Larry, Alvarado-Montes, Jaime A., Bender, Chad, Bernabò, Lia Marta, Blake, Cullen H., Cochran, William D., Diddams, Scott A., Halverson, Samuel, Han, Te, Hearty, Fred, Logsdon, Sarah E., Mahadevan, Suvrath, Monson, Andrew, McElwain, Michael, Robertson, Paul, Ojha, Devendra, Roy, Arpita, Schwab, Christian, Stefansson, Gudmundur, and Wright, Jason
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Astrophysics - Earth and Planetary Astrophysics - Abstract
We present the discovery of a low-density planet orbiting the high-metallicity early M-dwarf TOI-5688 A b. This planet was characterized as part of the search for transiting giant planets ($R \gtrsim8$ M${}_\oplus$) through the Searching for GEMS (Giant Exoplanets around M-dwarf Stars) survey. The planet was discovered with the Transiting Exoplanet Survey Satellite (TESS), and characterized with ground-based transits from Red Buttes Observatory (RBO), the Table Mountain Observatory of Pomona College, and radial velocity (RV) measurements with the Habitable-Zone Planet Finder (HPF) on the 10 m Hobby Eberly Telescope (HET) and NEID on the WIYN 3.5 m telescope. From the joint fit of transit and RV data, we measure a planetary mass and radius of $124\pm24$ M$_\oplus$ ($0.39\pm0.07$ M${}_J$) and $10.4\pm0.7$ R$_\oplus$ ($0.92\pm0.06$ R${}_J$) respectively. The spectroscopic and photometric analysis of the host star TOI-5688 A shows that it is a metal-rich ([Fe/H] $ = 0.47\pm0.16$ dex) M2V star, favoring the core-accretion formation pathway as the likely formation scenario for this planet. Additionally, Gaia astrometry suggests the presence of a wide-separation binary companion, TOI-5688 B, which has a projected separation of $\sim5"$ (1110 AU) and is an M4V, making TOI-5688 A b part of the growing number of GEMS in wide-separation binary systems., Comment: 20 pages, 7 figures, Accepted in AJ
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- 2024
31. Augmented Reality for the Development of Skilled Trades in Indigenous Communities: A Case Study
- Author
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Gonzalo Alfonso Beltrán Alvarado and Adriana Patricia Huertas Bustos
- Abstract
The main objective of this study was the design and validation of a mobile learning environment (ML) based on Augmented Reality (AR) visualization with the purpose of developing skilled trades in the field of carpentry in indigenous populations. A pedagogical model focused on lifelong learning was used, in order to promote the acquisition of skilled trades and knowledge in carpentry. The implementation of the ML environment was carried out in the Wayuu community, characterized by its high rate of poverty and limited access to education. During face-to-face meetings, three indigenous people participated in a learning process in which they were instructed on the use of trade tools and became familiar with the different types of trees and wood. To support this process, the AR was used together with the M-L environment. Subsequently, the participants built a chair applying the knowledge acquired during the learning process. During this stage, recordings of the indigenous people were made while they carried out the construction. Then, the performance of the apprentices was evaluated through a competency-based evaluation system, in which three experts analyzed the recordings. Finally, the three indigenous people were able to acquire skills in real time through their mobile device, following the instructions and observing 3D images and videos that showed the entire manufacturing process of a wooden chair, from sanding the material to final assembly and polishing. In addition, it was found that these indigenous people were able to successfully market the products they made in the carpentry workshop, thus improving their family income. The fundamental idea behind the pedagogical implementation of this model in the Wayuu indigenous community of northern Colombia is to provide them with training in various trades that allow them to obtain decent jobs and support their families. That is why the ML environment is ideal for vulnerable people, not only indigenous people, but also for those who are displaced, the elderly or deaf-mute. The visual approach used in this method dispenses with the need for voice and text making it accessible to everyone. [Note: The publication year shown on the PDF in the article citation, on page 1 (2023) is incorrect. The correct publication year is 2024.]
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- 2024
32. Teachers' Perceptions about the Use of Learning Management Systems during the COVID-19 Pandemic Considering Data Science
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Ricardo-Adan Salas-Rueda and Clara Alvarado-Zamorano
- Abstract
Technological advances such as Learning Management System (LMS) are changing the teaching-learning conditions, organization of school activities and functions of educators. In particular, the use of LMS in the educational field is necessary due to the appearance of the SARS-CoV-2 virus. This quantitative research analyzes the teachers' perception about the use of LMS during the COVID-19 pandemic considering data science. The sample is 115 teachers from the National Autonomous University of Mexico. These teachers took the "Classroom of the Future 2020" Diploma in order to create new educational spaces. The results of the machine learning technique indicate that the performance of the school activities in LMS positively influences the learning process, motivation and participation of the students during the COVID-19 pandemic. Also, the decision tree technique identifies three predictive models about the use of this technological tool in the educational field considering the academic level and sex of the teachers. In conclusion, educators can improve the learning conditions, organize creative activities inside and outside the classroom, achieve the innovation in the educational context and build virtual spaces through LMS.
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- 2024
33. Periods of Technological Change in Higher Education
- Author
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Miguel Casillas Alvarado, Alberto Ramirez Martinell, and Rosbenraver Lopez-Olivera Lopez
- Abstract
This study identifies three fundamental historical moments related to the incorporation of information and communication technologies in higher education. To explore these phases, we acknowledge an initial period defined by the massive use of computers, mostly for accounting and office automation; a second period during which highly specialized software emerges and expands its coverage in academic disciplines; and a third period characterized by a widespread use of Learning Management Systems and communication software during the COVID-19 pandemic.
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- 2024
34. Feature Optimization and Machine Learning for Predicting Students' Academic Performance in Higher Education Institutions
- Author
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Aom Perkash, Qaisar Shaheen, Robina Saleem, Furqan Rustam, Monica Gracia Villar, Eduardo Silva Alvarado, Isabel de la Torre Diez, and Imran Ashraf
- Abstract
Developing tools to support students, educators, intuitions, and government in the educational environment has become an important task to improve the quality of education and learning outcomes. Information and communication technology (ICT) is adopted by educational institutions; one such instance is video interaction in flipped teaching. ICT-based learning generates a huge amount of data that can be utilized to better understand student behavior and improve students learning. Predicting students' academic performance is essential to take proactive measures to improve student learning and reduce the risk of student dropout and failure. This study aims to use video learning analysis and data mining approaches to predict student academic achievement and identify the factors affecting their performance. For this purpose, the dataset containing records of 326 students from a higher education institution (HEI) is used which contains records from SIS, Moodle, and eDify. This study advocates the use of a balanced dataset and optimized feature set to obtain better performance for students' academic performance prediction. Several machine learning and deep learning models are applied to analyze their performance against the original dataset, balanced dataset, and balanced dataset with the optimized feature set. Experimental results demonstrate decision tree classifier outperforms with an accuracy of 99.06% with a balanced dataset and optimized feature set. Further analysis indicates that the video interaction feature has a strong impact on the performance of students.
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- 2024
- Full Text
- View/download PDF
35. Molecular Characterization and Photoreactivity of Organic Aerosols Formed from Pyrolysis of Urban Materials during Fires at the Wildland-Urban Interface.
- Author
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Hopstock, Katherine, Xie, Qiaorong, Alvarado, Michael, Moschos, Vaios, Bililign, Solomon, Surratt, Jason, Laskin, Alexander, and Nizkorodov, Sergey
- Abstract
Fires at the wildland-urban interface (WUI) are increasing in magnitude and frequency, emitting organic aerosol (OA) with unknown composition and atmospheric impacts. In this study, we investigated the chemical composition of OA produced through the 600 °C pyrolysis of ten urban materials in nitrogen, which were subsequently aged under UV light for 2 h. The analysis utilized ultrahigh-performance liquid chromatography (UHPLC) separation, coupled with a photodiode array (PDA) detector and a high-resolution mass spectrometer (HRMS) for molecular characterization. Hierarchical clustering analysis demonstrated that lumber-derived OA was the most diverse and distinct in composition. Unaged and aged OA (for each urban material) did not significantly differ in chemical identities. Potential aromatic brown carbon (BrC) chromophores (based on their degree of unsaturation) constituted 13-42% of all assigned compounds. PDA chromatograms revealed multiple BrC chromophoric species that were either enhanced or degraded as a result of UV aging, providing insights into specific BrC chromophores responsible for photobleaching and photoenhancement of the overall absorption coefficient. Thirty-six BrC chromophores were identified across the ten OA types, and their structures were confirmed using reference standards. Components of plasticizers and resins, such as phthalic and terephthalic acids, were structurally confirmed in the samples. We present potential species for WUI fires as components of resins, epoxies, dyes, and adhesives commonly used in manufacturing urban materials. Photolysis did not significantly impact the chemical composition of OA emitted from the burning of specific WUI materials.
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- 2024
36. Sharing the Coast: Opportunities and strategies for accelerating coastal resilience in the San Diego-Baja California Region
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Le Alvarado, Meliza, Engeman, Laura, and Pairis, Amber
- Subjects
coastal science ,baja - Abstract
The purpose of this document is to outline a strategic vision for enhancing coastal resilience in the San Diego-Baja California Region through binational collaboration. It draws from a needs assessment led by California Sea Grant and the Climate Science Alliance. This vision document identifies key opportunities and actionable strategies that integrate scientific research, traditional knowledge, and innovative practices to support resilient coastal communities and ecosystems. By fostering cross-border partnerships, expanding research capabilities, and engaging diverse stakeholders, this document aims to guide efforts towards a more resilient future for our shared coastline.
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- 2024
37. Compartiendo la Costa: Oportunidades y estrategias para la resiliencia costera en la región San Diego-Baja California
- Author
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Le Alvarado, Meliza, Engeman, Laura, and Pairis, Amber
- Subjects
coastal science ,baja - Abstract
El propósito de este documento es compartir una visión estratégica para mejorar la resiliencia costera en la región de San Diego-Baja California a través de la colaboración binacional basada en una evaluación de necesidades liderada por California Sea Grant y Climate Science Alliance.La visión de este documento identifica oportunidades clave y estrategias accionables que integran la investigación científica, el conocimiento tradicional y prácticas innovadoras para apoyar a las comunidades y ecosistemas costeros. Al fomentar asociaciones transfronterizas, expandir las capacidades de investigación y comprometer a diversos actores, este documento tiene como objetivo guiar los esfuerzos hacia un futuro más resiliente para nuestra costa compartida.
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- 2024
38. The global distribution and drivers of wood density and their impact on forest carbon stocks.
- Author
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Mo, Lidong, Crowther, Thomas W, Maynard, Daniel S, van den Hoogen, Johan, Ma, Haozhi, Bialic-Murphy, Lalasia, Liang, Jingjing, de-Miguel, Sergio, Nabuurs, Gert-Jan, Reich, Peter B, Phillips, Oliver L, Abegg, Meinrad, Adou Yao, Yves C, Alberti, Giorgio, Almeyda Zambrano, Angelica M, Alvarado, Braulio Vilchez, Alvarez-Dávila, Esteban, Alvarez-Loayza, Patricia, Alves, Luciana F, Amaral, Iêda, Ammer, Christian, Antón-Fernández, Clara, Araujo-Murakami, Alejandro, Arroyo, Luzmila, Avitabile, Valerio, Aymard, Gerardo A, Baker, Timothy R, Bałazy, Radomir, Banki, Olaf, Barroso, Jorcely G, Bastian, Meredith L, Bastin, Jean-Francois, Birigazzi, Luca, Birnbaum, Philippe, Bitariho, Robert, Boeckx, Pascal, Bongers, Frans, Boonman, Coline CF, Bouriaud, Olivier, Brancalion, Pedro HS, Brandl, Susanne, Brearley, Francis Q, Brienen, Roel, Broadbent, Eben N, Bruelheide, Helge, Bussotti, Filippo, Gatti, Roberto Cazzolla, César, Ricardo G, Cesljar, Goran, Chazdon, Robin, Chen, Han YH, Chisholm, Chelsea, Cho, Hyunkook, Cienciala, Emil, Clark, Connie, Clark, David, Colletta, Gabriel D, Coomes, David A, Valverde, Fernando Cornejo, Corral-Rivas, José J, Crim, Philip M, Cumming, Jonathan R, Dayanandan, Selvadurai, de Gasper, André L, Decuyper, Mathieu, Derroire, Géraldine, DeVries, Ben, Djordjevic, Ilija, Dolezal, Jiri, Dourdain, Aurélie, Engone Obiang, Nestor Laurier, Enquist, Brian J, Eyre, Teresa J, Fandohan, Adandé Belarmain, Fayle, Tom M, Feldpausch, Ted R, Ferreira, Leandro V, Finér, Leena, Fischer, Markus, Fletcher, Christine, Frizzera, Lorenzo, Gamarra, Javier GP, Gianelle, Damiano, Glick, Henry B, Harris, David J, Hector, Andrew, Hemp, Andreas, Hengeveld, Geerten, Hérault, Bruno, Herbohn, John L, Herold, Martin, Hietz, Peter, Hillers, Annika, Honorio Coronado, Eurídice N, Hui, Cang, Ibanez, Thomas, Imai, Nobuo, Jagodziński, Andrzej M, Jaroszewicz, Bogdan, and Johannsen, Vivian Kvist
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Ecology ,Evolutionary biology ,Environmental management - Abstract
The density of wood is a key indicator of the carbon investment strategies of trees, impacting productivity and carbon storage. Despite its importance, the global variation in wood density and its environmental controls remain poorly understood, preventing accurate predictions of global forest carbon stocks. Here we analyse information from 1.1 million forest inventory plots alongside wood density data from 10,703 tree species to create a spatially explicit understanding of the global wood density distribution and its drivers. Our findings reveal a pronounced latitudinal gradient, with wood in tropical forests being up to 30% denser than that in boreal forests. In both angiosperms and gymnosperms, hydrothermal conditions represented by annual mean temperature and soil moisture emerged as the primary factors influencing the variation in wood density globally. This indicates similar environmental filters and evolutionary adaptations among distinct plant groups, underscoring the essential role of abiotic factors in determining wood density in forest ecosystems. Additionally, our study highlights the prominent role of disturbance, such as human modification and fire risk, in influencing wood density at more local scales. Factoring in the spatial variation of wood density notably changes the estimates of forest carbon stocks, leading to differences of up to 21% within biomes. Therefore, our research contributes to a deeper understanding of terrestrial biomass distribution and how environmental changes and disturbances impact forest ecosystems.
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- 2024
39. PM2.5 exposure disparities persist despite strict vehicle emissions controls in California.
- Author
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Koolik, Libby, Alvarado, Álvaro, Budahn, Amy, Plummer, Laurel, Marshall, Julian, and Apte, Joshua
- Subjects
California ,Vehicle Emissions ,Particulate Matter ,Humans ,Air Pollution ,Environmental Exposure ,Air Pollutants - Abstract
As policymakers increasingly focus on environmental justice, a key question is whether emissions reductions aimed at addressing air quality or climate change can also ameliorate persistent air pollution exposure disparities. We examine evidence from Californias aggressive vehicle emissions control policy from 2000 to 2019. We find a 65% reduction in modeled statewide average exposure to PM2.5 from on-road vehicles, yet for people of color and overburdened community residents, relative exposure disparities increased. Light-duty vehicle emissions are the main driver of the exposure and exposure disparity, although smaller contributions from heavy-duty vehicles especially affect some overburdened groups. Our findings suggest that a continued trend of emissions reductions will likely reduce concentrations and absolute disparity but may not reduce relative disparities without greater attention to the systemic factors leading to this disparity.
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- 2024
40. Assessing innovations for upscaling forest landscape restoration
- Author
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Werden, Leland K, Cole, Rebecca J, Schönhofer, Katrin, Holl, Karen D, Zahawi, Rakan A, Averill, Colin, Schweizer, Daniella, Calvo-Alvarado, Julio C, Hamilton, Debra, Joyce, Francis H, San-José, Miriam, Hofhansl, Florian, Briggs, Lilly, Rodríguez, David, Tingle, Jeffrey W, Chiriboga, Fidel, Broadbent, Eben N, Quirós-Cedeño, Gerald J, and Crowther, Thomas W
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Climate Change Impacts and Adaptation ,Ecological Applications ,Environmental Sciences ,Life on Land ,Earth sciences ,Environmental sciences - Published
- 2024
41. Rate-adaptive Reconciliation for Experimental Continuous-variable Quantum Key Distribution with Discrete Modulation over a Free-space Optical Link
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Gümüş, Kadir, Frazão, João dos Reis, van Vliet, Vincent, van der Heide, Sjoerd, Hout, Menno van den, Liga, Gabriele, Gültekin, Yunus Can, Albores-Mejia, Aaron, Bradley, Thomas, Alvarado, Alex, and Okonkwo, Chigo
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Quantum Physics - Abstract
Continuous-variable quantum key distribution (CV-QKD) has been proposed as a method for securely exchanging keys to protect against the security concerns caused by potential advancements in quantum computing. In addition to optical fibre transmission, the free-space optical (FSO) channel is an interesting channel for CV-QKD, as it is possible to share keys over this channel wirelessly. The instability of the FSO channel caused by turbulence-induced fading, however, can cause a degradation in the system's performance. One of the most important aspects of CV-QKD is the reconciliation step, which significantly impacts the performance of the CV-QKD system. Hence, rate-adaptive reconciliation is necessary for CV-QKD over FSO to combat the fluctuations in the channel and improve secret key rates (SKRs). Therefore, in this paper, we simulate the impact of discrete modulation on the reconciliation efficiency and consider the use of $d$-dimensional reconciliation with $d > 8$ to mitigate this impact, improving reconciliation efficiencies by up to 3.4%. We validate our results by experimentally demonstrating CV-QKD over a turbulent FSO link and demonstrate SKR gains by up to 165%. Furthermore, we optimise the reconciliation efficiency for FSO links, achieving additional SKR gains of up to 7.6%., Comment: Pre-print JLT
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- 2024
42. Any Graph is a Mapper Graph
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Alvarado, Enrique G, Belton, Robin, Lee, Kang-Ju, Palande, Sourabh, Percival, Sarah, Purvine, Emilie, and Tymochko, Sarah
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Mathematics - Algebraic Topology ,Computer Science - Computational Geometry - Abstract
The Mapper algorithm is a popular tool for visualization and data exploration in topological data analysis. We investigate an inverse problem for the Mapper algorithm: Given a dataset $X$ and a graph $G$, does there exist a set of Mapper parameters such that the output Mapper graph of $X$ is isomorphic to $G$? We provide constructions that affirmatively answer this question. Our results demonstrate that it is possible to engineer Mapper parameters to generate a desired graph., Comment: 13 pages, 4 figures
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- 2024
43. The missing rings around Solar System moons
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Sucerquia, Mario, Alvarado-Montes, Jaime A., Zuluaga, Jorge I., Cuello, Nicolás, Cuadra, Jorge, and Montesinos, Matías
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Astrophysics - Earth and Planetary Astrophysics - Abstract
Rings are complex structures surrounding giant planets and some minor bodies in the Solar System. While some formation mechanisms could also potentially foster their existence around (regular or irregular) satellites, none of these bodies currently bear these structures. We aim to understand the underlying mechanisms that govern the potential formation, stability, and/or decay of hypothetical circumsatellital rings (CSRs), orbiting the largest moons in the Solar System. This extends to the exploration of short-term morphological features within these rings, providing insights into the ring survival time-scales and the interactions that drive their evolution. To conduct this study, we use numerical N-body simulations under the perturbing influence of the host planet and other moon companions. We found that moons with a lower Roche-to-Hill radius can preserve their rings over extended periods. Moreover, the gravitational environment in which these rings are immersed influences the system's morphological evolution, inducing gaps through the excitation of eccentricity and inclination of constituent particles. Specifically, our results show that Iapetus' and Rhea's rings experience minimal variations in their orbital parameters, enhancing their long-term stability. This agrees with the hypothesis that some of the features of Iapetus and Rhea were produced by ancient ring systems, for example, the huge ridge in Iapetus equator as a result of a decaying ring. From a dynamical perspective, we found that there are no mechanisms that preclude the existence of CSRs and we attribute their current absence to non-gravitational phenomena. Effects such as stellar radiation, magnetic fields, and the influence of magnetospheric plasma can significantly impact the dynamics of constituent particles and trigger their decay, highlighing the importance of future studies on these effects., Comment: Accepted for publication in Astronomy & Astrophysics
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- 2024
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44. Mechanical design concept version 2.0 for the miniBeBe subsystem of the Multi-Purpose Detector at the Nuclotron-based Ion Collider fAcility of the Joint Institute for Nuclear Research
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Herrera, M., Patiño, M. E., Alvarado, Mauricio, Maldonado, Ivonne, Andreev, Denis, Ayala, Alejandro, Bietenholz, Wolfgang, Ceballos, César, Cuáutle, Eleazar, Domínguez, Isabel, Hernández, L. A., Luna, Israel, Lygdenova, Tuyana, Martínez-Torres, Pablo, Raya, Alfredo, Sáenz-Trujillo, Ulises, Tejeda-Yeomans, M. E., and Tinoco-Santillán, Galileo
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Physics - Instrumentation and Detectors - Abstract
We present the design of the mechanical structure of the miniBeBe detector, a subsystem of the Multi-Purpose Detector, soon to enter into operation at the Nuclotron based Ion Collider fAcility of the Joint Institute for Nuclear Research. The miniBeBe detector was designed and is currently being developed by the MexNICA Collaboration to contribute to the level-zero trigger of the Time of Flight. The mechanical structure meets the requirements of minimizing the material budget and be free of ferromagnetic materials, without compromising its robustness. The design also allows easy module replacement for maintenance and overall removal at the end of the first stage of the experiment, without affecting the rest of the subsystems, to leave room for the installation of the Inner Tracking System. In addition, a Finite Element Method analysis of the mechanical components under load was performed. Based on this analysis, it was determined that the design meets the space constraints within the Multi-Purpose Detector, as well as a deformation of less than 1 mm with overall stress of less than 2 MPa, such that no material used in the design is at risk of mechanical failure during operation. A cooling system heat transfer analysis was performed showing that the detector Silicon Photo-Multipliers can be kept within a temperature range of 19$^{\circ}$C to 23$^{\circ}$C, which is adequate for their optimal performance., Comment: 15 pages, 13 figures, 6 tables
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- 2024
45. The Llama 3 Herd of Models
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Grattafiori, Aaron, Dubey, Abhimanyu, Jauhri, Abhinav, Pandey, Abhinav, Kadian, Abhishek, Al-Dahle, Ahmad, Letman, Aiesha, Mathur, Akhil, Schelten, Alan, Vaughan, Alex, Yang, Amy, Fan, Angela, Goyal, Anirudh, Hartshorn, Anthony, Yang, Aobo, Mitra, Archi, Sravankumar, Archie, Korenev, Artem, Hinsvark, Arthur, Rao, Arun, Zhang, Aston, Rodriguez, Aurelien, Gregerson, Austen, Spataru, Ava, Roziere, Baptiste, Biron, Bethany, Tang, Binh, Chern, Bobbie, Caucheteux, Charlotte, Nayak, Chaya, Bi, Chloe, Marra, Chris, McConnell, Chris, Keller, Christian, Touret, Christophe, Wu, Chunyang, Wong, Corinne, Ferrer, Cristian Canton, Nikolaidis, Cyrus, Allonsius, Damien, Song, Daniel, Pintz, Danielle, Livshits, Danny, Wyatt, Danny, Esiobu, David, Choudhary, Dhruv, Mahajan, Dhruv, Garcia-Olano, Diego, Perino, Diego, Hupkes, Dieuwke, Lakomkin, Egor, AlBadawy, Ehab, Lobanova, Elina, Dinan, Emily, Smith, Eric Michael, Radenovic, Filip, Guzmán, Francisco, Zhang, Frank, Synnaeve, Gabriel, Lee, Gabrielle, Anderson, Georgia Lewis, Thattai, Govind, Nail, Graeme, Mialon, Gregoire, Pang, Guan, Cucurell, Guillem, Nguyen, Hailey, Korevaar, Hannah, Xu, Hu, Touvron, Hugo, Zarov, Iliyan, Ibarra, Imanol Arrieta, Kloumann, Isabel, Misra, Ishan, Evtimov, Ivan, Zhang, Jack, Copet, Jade, Lee, Jaewon, Geffert, Jan, Vranes, Jana, Park, Jason, Mahadeokar, Jay, Shah, Jeet, van der Linde, Jelmer, Billock, Jennifer, Hong, Jenny, Lee, Jenya, Fu, Jeremy, Chi, Jianfeng, Huang, Jianyu, Liu, Jiawen, Wang, Jie, Yu, Jiecao, Bitton, Joanna, Spisak, Joe, Park, Jongsoo, Rocca, Joseph, Johnstun, Joshua, Saxe, Joshua, Jia, Junteng, Alwala, Kalyan Vasuden, Prasad, Karthik, Upasani, Kartikeya, Plawiak, Kate, Li, Ke, Heafield, Kenneth, Stone, Kevin, El-Arini, Khalid, Iyer, Krithika, Malik, Kshitiz, Chiu, Kuenley, Bhalla, Kunal, Lakhotia, Kushal, Rantala-Yeary, Lauren, van der Maaten, Laurens, Chen, Lawrence, Tan, Liang, Jenkins, Liz, Martin, Louis, Madaan, Lovish, Malo, Lubo, Blecher, Lukas, Landzaat, Lukas, de Oliveira, Luke, Muzzi, Madeline, Pasupuleti, Mahesh, Singh, Mannat, Paluri, Manohar, Kardas, Marcin, Tsimpoukelli, Maria, Oldham, Mathew, Rita, Mathieu, Pavlova, Maya, Kambadur, Melanie, Lewis, Mike, Si, Min, Singh, Mitesh Kumar, Hassan, Mona, Goyal, Naman, Torabi, Narjes, Bashlykov, Nikolay, Bogoychev, Nikolay, Chatterji, Niladri, Zhang, Ning, Duchenne, Olivier, Çelebi, Onur, Alrassy, Patrick, Zhang, Pengchuan, Li, Pengwei, Vasic, Petar, Weng, Peter, Bhargava, Prajjwal, Dubal, Pratik, Krishnan, Praveen, Koura, Punit Singh, Xu, Puxin, He, Qing, Dong, Qingxiao, Srinivasan, Ragavan, Ganapathy, Raj, Calderer, Ramon, Cabral, Ricardo Silveira, Stojnic, Robert, Raileanu, Roberta, Maheswari, Rohan, Girdhar, Rohit, Patel, Rohit, Sauvestre, Romain, Polidoro, Ronnie, Sumbaly, Roshan, Taylor, Ross, Silva, Ruan, Hou, Rui, Wang, Rui, Hosseini, Saghar, Chennabasappa, Sahana, Singh, Sanjay, Bell, Sean, Kim, Seohyun Sonia, Edunov, Sergey, Nie, Shaoliang, Narang, Sharan, Raparthy, Sharath, Shen, Sheng, Wan, Shengye, Bhosale, Shruti, Zhang, Shun, Vandenhende, Simon, Batra, Soumya, Whitman, Spencer, Sootla, Sten, Collot, Stephane, Gururangan, Suchin, Borodinsky, Sydney, Herman, Tamar, Fowler, Tara, Sheasha, Tarek, Georgiou, Thomas, Scialom, Thomas, Speckbacher, Tobias, Mihaylov, Todor, Xiao, Tong, Karn, Ujjwal, Goswami, Vedanuj, Gupta, Vibhor, Ramanathan, Vignesh, Kerkez, Viktor, Gonguet, Vincent, Do, Virginie, Vogeti, Vish, Albiero, Vítor, Petrovic, Vladan, Chu, Weiwei, Xiong, Wenhan, Fu, Wenyin, Meers, Whitney, Martinet, Xavier, Wang, Xiaodong, Wang, Xiaofang, Tan, Xiaoqing Ellen, Xia, Xide, Xie, Xinfeng, Jia, Xuchao, Wang, Xuewei, Goldschlag, Yaelle, Gaur, Yashesh, Babaei, Yasmine, Wen, Yi, Song, Yiwen, Zhang, Yuchen, Li, Yue, Mao, Yuning, Coudert, Zacharie Delpierre, Yan, Zheng, Chen, Zhengxing, Papakipos, Zoe, Singh, Aaditya, Srivastava, Aayushi, Jain, Abha, Kelsey, Adam, Shajnfeld, Adam, Gangidi, Adithya, Victoria, Adolfo, Goldstand, Ahuva, Menon, Ajay, Sharma, Ajay, Boesenberg, Alex, Baevski, Alexei, Feinstein, Allie, Kallet, Amanda, Sangani, Amit, Teo, Amos, Yunus, Anam, Lupu, Andrei, Alvarado, Andres, Caples, Andrew, Gu, Andrew, Ho, Andrew, Poulton, Andrew, Ryan, Andrew, Ramchandani, Ankit, Dong, Annie, Franco, Annie, Goyal, Anuj, Saraf, Aparajita, Chowdhury, Arkabandhu, Gabriel, Ashley, Bharambe, Ashwin, Eisenman, Assaf, Yazdan, Azadeh, James, Beau, Maurer, Ben, Leonhardi, Benjamin, Huang, Bernie, Loyd, Beth, De Paola, Beto, Paranjape, Bhargavi, Liu, Bing, Wu, Bo, Ni, Boyu, Hancock, Braden, Wasti, Bram, Spence, Brandon, Stojkovic, Brani, Gamido, Brian, Montalvo, Britt, Parker, Carl, Burton, Carly, Mejia, Catalina, Liu, Ce, Wang, Changhan, Kim, Changkyu, Zhou, Chao, Hu, Chester, Chu, Ching-Hsiang, Cai, Chris, Tindal, Chris, Feichtenhofer, Christoph, Gao, Cynthia, Civin, Damon, Beaty, Dana, Kreymer, Daniel, Li, Daniel, Adkins, David, Xu, David, Testuggine, Davide, David, Delia, Parikh, Devi, Liskovich, Diana, Foss, Didem, Wang, Dingkang, Le, Duc, Holland, Dustin, Dowling, Edward, Jamil, Eissa, Montgomery, Elaine, Presani, Eleonora, Hahn, Emily, Wood, Emily, Le, Eric-Tuan, Brinkman, Erik, Arcaute, Esteban, Dunbar, Evan, Smothers, Evan, Sun, Fei, Kreuk, Felix, Tian, Feng, Kokkinos, Filippos, Ozgenel, Firat, Caggioni, Francesco, Kanayet, Frank, Seide, Frank, Florez, Gabriela Medina, Schwarz, Gabriella, Badeer, Gada, Swee, Georgia, Halpern, Gil, Herman, Grant, Sizov, Grigory, Guangyi, Zhang, Lakshminarayanan, Guna, Inan, Hakan, Shojanazeri, Hamid, Zou, Han, Wang, Hannah, Zha, Hanwen, Habeeb, Haroun, Rudolph, Harrison, Suk, Helen, Aspegren, Henry, Goldman, Hunter, Zhan, Hongyuan, Damlaj, Ibrahim, Molybog, Igor, Tufanov, Igor, Leontiadis, Ilias, Veliche, Irina-Elena, Gat, Itai, Weissman, Jake, Geboski, James, Kohli, James, Lam, Janice, Asher, Japhet, Gaya, Jean-Baptiste, Marcus, Jeff, Tang, Jeff, Chan, Jennifer, Zhen, Jenny, Reizenstein, Jeremy, Teboul, Jeremy, Zhong, Jessica, Jin, Jian, Yang, Jingyi, Cummings, Joe, Carvill, Jon, Shepard, Jon, McPhie, Jonathan, Torres, Jonathan, Ginsburg, Josh, Wang, Junjie, Wu, Kai, U, Kam Hou, Saxena, Karan, Khandelwal, Kartikay, Zand, Katayoun, Matosich, Kathy, Veeraraghavan, Kaushik, Michelena, Kelly, Li, Keqian, Jagadeesh, Kiran, Huang, Kun, Chawla, Kunal, Huang, Kyle, Chen, Lailin, Garg, Lakshya, A, Lavender, Silva, Leandro, Bell, Lee, Zhang, Lei, Guo, Liangpeng, Yu, Licheng, Moshkovich, Liron, Wehrstedt, Luca, Khabsa, Madian, Avalani, Manav, Bhatt, Manish, Mankus, Martynas, Hasson, Matan, Lennie, Matthew, Reso, Matthias, Groshev, Maxim, Naumov, Maxim, Lathi, Maya, Keneally, Meghan, Liu, Miao, Seltzer, Michael L., Valko, Michal, Restrepo, Michelle, Patel, Mihir, Vyatskov, Mik, Samvelyan, Mikayel, Clark, Mike, Macey, Mike, Wang, Mike, Hermoso, Miquel Jubert, Metanat, Mo, Rastegari, Mohammad, Bansal, Munish, Santhanam, Nandhini, Parks, Natascha, White, Natasha, Bawa, Navyata, Singhal, Nayan, Egebo, Nick, Usunier, Nicolas, Mehta, Nikhil, Laptev, Nikolay Pavlovich, Dong, Ning, Cheng, Norman, Chernoguz, Oleg, Hart, Olivia, Salpekar, Omkar, Kalinli, Ozlem, Kent, Parkin, Parekh, Parth, Saab, Paul, Balaji, Pavan, Rittner, Pedro, Bontrager, Philip, Roux, Pierre, Dollar, Piotr, Zvyagina, Polina, Ratanchandani, Prashant, Yuvraj, Pritish, Liang, Qian, Alao, Rachad, Rodriguez, Rachel, Ayub, Rafi, Murthy, Raghotham, Nayani, Raghu, Mitra, Rahul, Parthasarathy, Rangaprabhu, Li, Raymond, Hogan, Rebekkah, Battey, Robin, Wang, Rocky, Howes, Russ, Rinott, Ruty, Mehta, Sachin, Siby, Sachin, Bondu, Sai Jayesh, Datta, Samyak, Chugh, Sara, Hunt, Sara, Dhillon, Sargun, Sidorov, Sasha, Pan, Satadru, Mahajan, Saurabh, Verma, Saurabh, Yamamoto, Seiji, Ramaswamy, Sharadh, Lindsay, Shaun, Feng, Sheng, Lin, Shenghao, Zha, Shengxin Cindy, Patil, Shishir, Shankar, Shiva, Zhang, Shuqiang, Wang, Sinong, Agarwal, Sneha, Sajuyigbe, Soji, Chintala, Soumith, Max, Stephanie, Chen, Stephen, Kehoe, Steve, Satterfield, Steve, Govindaprasad, Sudarshan, Gupta, Sumit, Deng, Summer, Cho, Sungmin, Virk, Sunny, Subramanian, Suraj, Choudhury, Sy, Goldman, Sydney, Remez, Tal, Glaser, Tamar, Best, Tamara, Koehler, Thilo, Robinson, Thomas, Li, Tianhe, Zhang, Tianjun, Matthews, Tim, Chou, Timothy, Shaked, Tzook, Vontimitta, Varun, Ajayi, Victoria, Montanez, Victoria, Mohan, Vijai, Kumar, Vinay Satish, Mangla, Vishal, Ionescu, Vlad, Poenaru, Vlad, Mihailescu, Vlad Tiberiu, Ivanov, Vladimir, Li, Wei, Wang, Wenchen, Jiang, Wenwen, Bouaziz, Wes, Constable, Will, Tang, Xiaocheng, Wu, Xiaojian, Wang, Xiaolan, Wu, Xilun, Gao, Xinbo, Kleinman, Yaniv, Chen, Yanjun, Hu, Ye, Jia, Ye, Qi, Ye, Li, Yenda, Zhang, Yilin, Zhang, Ying, Adi, Yossi, Nam, Youngjin, Yu, Wang, Zhao, Yu, Hao, Yuchen, Qian, Yundi, Li, Yunlu, He, Yuzi, Rait, Zach, DeVito, Zachary, Rosnbrick, Zef, Wen, Zhaoduo, Yang, Zhenyu, Zhao, Zhiwei, and Ma, Zhiyu
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Computer Science - Artificial Intelligence ,Computer Science - Computation and Language ,Computer Science - Computer Vision and Pattern Recognition - Abstract
Modern artificial intelligence (AI) systems are powered by foundation models. This paper presents a new set of foundation models, called Llama 3. It is a herd of language models that natively support multilinguality, coding, reasoning, and tool usage. Our largest model is a dense Transformer with 405B parameters and a context window of up to 128K tokens. This paper presents an extensive empirical evaluation of Llama 3. We find that Llama 3 delivers comparable quality to leading language models such as GPT-4 on a plethora of tasks. We publicly release Llama 3, including pre-trained and post-trained versions of the 405B parameter language model and our Llama Guard 3 model for input and output safety. The paper also presents the results of experiments in which we integrate image, video, and speech capabilities into Llama 3 via a compositional approach. We observe this approach performs competitively with the state-of-the-art on image, video, and speech recognition tasks. The resulting models are not yet being broadly released as they are still under development.
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- 2024
46. Jets-separation thresholds, Seshadri constants and higher Gauss-Wahl maps on abelian varieties
- Author
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Alvarado, Nelson
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Mathematics - Algebraic Geometry - Abstract
Given a closed subscheme $Z$ of a polarized abelian variety $(A,\ell)$ we define its vanishing threshold with respect to $\ell$ and relate it to the Seshadri constant of the ideal defining $Z.$ As a particular case, we introduce the notion of jets-separation thresholds, which naturally arise as the vanishing threshold of the $p$-infinitesimal neighborhood of a point. Afterwards, by means of Fourier-Mukai methods we relate the jets-separation thresholds with the surjectivity of certain higher Gauss-Wahl maps. As a consequence we obtain a criterion for the surjectivity of those maps in terms of the Seshadri constant of the polarization $\ell.$, Comment: 22 pages
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- 2024
47. Semihomogenous vector bundles, $\mathbb Q$-twisted sheaves, duality, and linear systems on abelian varieties
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Alvarado, Nelson and Pareschi, Giuseppe
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Mathematics - Algebraic Geometry - Abstract
In this paper we point out the natural relation between $\mathbb Q$-twisted objects of the derived category of abelian varieties, cohomological rank functions, and semihomogeneous vector bundles. We apply this to two basic classes of corresponding objects via the Fourier-Mukai-Poincar\'e transform: positive twists of the ideal sheaf of one point, and evaluation complexes of ample semihomogeneous vector bundles. This leads to $\mathbb Q^{\ge 0}$- graded section modules associated to line bundles on abelian varieties (containing the usual section rings), built by means of semihomogeneous vector bundles. We prove a duality relation between such section modules associated to dual polarizations. Other applications include formulas relating the thresholds of relevant cohomological rank functions appearing in this context. As a consequence we produce non-trivial obstructions to surjectivity of multiplication maps of global sections of certain line bundles., Comment: 19 pages
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- 2024
48. Quantum Entanglement, Quantum Teleportation, Multilinear Polynomials and Geometry
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Romero, Juan M., Montoya-Gonzalez, Emiliano, and Velazquez-Alvarado, Oscar
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Quantum Physics - Abstract
We show that quantum entanglement states are associated with multilinear polynomials that cannot be factored. By using these multilinear polynomials, we propose a geometric representation for entanglement states. In particular, we show that the Bell's states are associated with non-factorable real multilinear polynomial, which can be represented geometrically by three-dimensional surfaces. Furthermore, in this framework, we show that a quantum circuit can be seen as a geometric transformations of plane geometry. This phenomenon is analogous to gravity, where matter curves space-time. In addition, we show an analogy between quantum teleportation and operations involving multilinear polynomials., Comment: 16 pages, 2 figures. Minor corrections. Comments welcome
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- 2024
49. ANDES, the high resolution spectrograph for the ELT: science goals, project overview and future developments
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Marconi, A., Abreu, M., Adibekyan, V., Alberti, V., Albrecht, S., Alcaniz, J., Aliverti, M., Prieto, C. Allende, Gómez, J. D. Alvarado, Alves, C. S., Amado, P. J., Amate, M., Andersen, M. I., Antoniucci, S., Artigau, E., Bailet, C., Baker, C., Baldini, V., Balestra, A., Barnes, S. A., Baron, F., Barros, S. C. C., Bauer, S. M., Beaulieu, M., Bellido-Tirado, O., Benneke, B., Bensby, T., Bergin, E. A., Berio, P., Biazzo, K., Bigot, L., Bik, A., Birkby, J. L., Blind, N., Boebion, O., Boisse, I., Bolmont, E., Bolton, J. S., Bonaglia, M., Bonfils, X., Bonhomme, L., Borsa, F., Bouret, J. -C., Brandeker, A., Brandner, W., Broeg, C. H., Brogi, M., Brousseau, D., Brucalassi, A., Brynnel, J., Buchhave, L. A., Buscher, D. F., Cabona, L., Cabral, A., Calderone, G., Calvo-Ortega, R., Cantalloube, F., Martins, B. L. Canto, Carbonaro, L., Caujolle, Y., Chauvin, G., Chazelas, B., Cheffot, A. -L., Cheng, Y. S., Chiavassa, A., Christensen, L., Cirami, R., Cirasuolo, M., Cook, N. J., Cooke, R. J., Coretti, I., Covino, S., Cowan, N., Cresci, G., Cristiani, S., Parro, V. Cunha, Cupani, G., D'Odorico, V., Dadi, K., Leão, I. de Castro, De Cia, A., De Medeiros, J. R., Debras, F., Debus, M., Delorme, A., Demangeon, O., Derie, F., Dessauges-Zavadsky, M., Di Marcantonio, P., Di Stefano, S., Dionies, F., de Souza, A. Domiciano, Doyon, R., Dunn, J., Egner, S., Ehrenreich, D., Faria, J. P., Ferruzzi, D., Feruglio, C., Fisher, M., Fontana, A., Frank, B. S., Fuesslein, C., Fumagalli, M., Fusco, T., Fynbo, J., Gabella, O., Gaessler, W., Gallo, E., Gao, X., Genolet, L., Genoni, M., Giacobbe, P., Giro, E., Goncalves, R. S., Gonzalez, O. A., Hernández, J. I. González, Gouvret, C., Temich, F. Gracia, Haehnelt, M. G., Haniff, C., Hatzes, A., Helled, R., Hoeijmakers, H. J., Hughes, I., Huke, P., Ivanisenko, Y., Järvinen, A. S., Järvinen, S. P., Kaminski, A., Kern, J., Knoche, J., Kordt, A., Korhonen, H., Korn, A. J., Kouach, D., Kowzan, G., Kreidberg, L., Landoni, M., Lanotte, A. A., Lavail, A., Lavie, B., Lee, D., Lehmitz, M., Li, J., Li, W., Liske, J., Lovis, C., Lucatello, S., Lunney, D., MacIntosh, M. J., Madhusudhan, N., Magrini, L., Maiolino, R., Maldonado, J., Malo, L., Man, A. W. S., Marquart, T., Marques, C. M. J., Marques, E. L., Martinez, P., Martins, A., Martins, C. J. A. P., Martins, J. H. C., Maslowski, P., Mason, C. A., Mason, E., McCracken, R. A., Sousa, M. A. F. Melo e, Mergo, P., Micela, G., Milaković, D., Molliere, P., Monteiro, M. A., Montgomery, D., Mordasini, C., Morin, J., Mucciarelli, A., Murphy, M. T., N'Diaye, M., Nardetto, N., Neichel, B., Neri, N., Niedzielski, A. T., Niemczura, E., Nisini, B., Nortmann, L., Noterdaeme, P., Nunes, N. J., Oggioni, L., Olchewsky, F., Oliva, E., Onel, H., Origlia, L., Ostlin, G., Ouellette, N. N. -Q., Palle, E., Papaderos, P., Pariani, G., Pasquini, L., Castro, J. Peñate, Pepe, F., Peroux, C., Levasseur, L. Perreault, Perruchot, S., Petit, P., Pfuhl, O., Pino, L., Piqueras, J., Piskunov, N., Pollo, A., Poppenhaeger, K., Porru, M., Puschnig, J., Quirrenbach, A., Rauscher, E., Rebolo, R., Redaelli, E. M. A., Reffert, S., Reid, D. T., Reiners, A., Richter, P., Riva, M., Rivoire, S., Rodriguez-López, C., Roederer, I. U., Romano, D., Roth, M., Rousseau, S., Rowe, J., Saccardi, A., Salvadori, S., Sanna, N., Santos, N. C., Diaz, P. Santos, Sanz-Forcada, J., Sarajlic, M., Sauvage, J. -F., Savio, D., Scaudo, A, Schäfer, S., Schiavon, R. P., Schmidt, T. M., Selmi, C., Simoes, R., Simonnin, A., Sivanandam, S., Sordet, M., Sordo, R., Sortino, F., Sosnowska, D., Sousa, S. G., Spang, A., Spiga, R., Stempels, E., Stevenson, J. R. Y., Strassmeier, K. G., Mascareño, A. Suárez, Sulich, A., Sun, X., Tanvir, N. R., Tenegi-Sangines, F., Thibault, S., Thompson, S. J., Tisserand, P., Tozzi, A., Turbet, M., Veran, J. -P., Vallee, P., Vanni, I., Varas, R., Vega-Moreno, A., Venn, K. A., Verma, A., Vernet, J., Viel, M., Wade, G., Waring, C., Weber, M., Weder, J., Wehbe, B., Weingrill, J., Woche, M., Xompero, M., Zackrisson, E., Zanutta, A., Osorio, M. R. Zapatero, Zechmeister, M., and Zimara, J.
- Subjects
Astrophysics - Instrumentation and Methods for Astrophysics - Abstract
The first generation of ELT instruments includes an optical-infrared high-resolution spectrograph, indicated as ELT-HIRES and recently christened ANDES (ArmazoNes high Dispersion Echelle Spectrograph). ANDES consists of three fibre-fed spectrographs ([U]BV, RIZ, YJH) providing a spectral resolution of $\sim$100,000 with a minimum simultaneous wavelength coverage of 0.4-1.8 $\mu$m with the goal of extending it to 0.35-2.4 $\mu$m with the addition of a U arm to the BV spectrograph and a separate K band spectrograph. It operates both in seeing- and diffraction-limited conditions and the fibre feeding allows several, interchangeable observing modes including a single conjugated adaptive optics module and a small diffraction-limited integral field unit in the NIR. Modularity and fibre-feeding allow ANDES to be placed partly on the ELT Nasmyth platform and partly in the Coud\'e room. ANDES has a wide range of groundbreaking science cases spanning nearly all areas of research in astrophysics and even fundamental physics. Among the top science cases, there are the detection of biosignatures from exoplanet atmospheres, finding the fingerprints of the first generation of stars, tests on the stability of Nature's fundamental couplings, and the direct detection of the cosmic acceleration. The ANDES project is carried forward by a large international consortium, composed of 35 Institutes from 13 countries, forming a team of almost 300 scientists and engineers which include the majority of the scientific and technical expertise in the field that can be found in ESO member states., Comment: SPIE astronomical telescope and instrumentation 2024, in press
- Published
- 2024
50. Frustrated Ising charge correlations in the kagome metal ScV$_6$Sn$_6$
- Author
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Alvarado, S. J. Gomez, Pokharel, G., Ortiz, B. R., Paddison, Joseph A. M., Sarker, Suchismita, Ruff, J. P. C., and Wilson, Stephen D.
- Subjects
Condensed Matter - Strongly Correlated Electrons - Abstract
Here we resolve the real-space nature of the high-temperature, short-range charge correlations in the kagome metal ScV$_6$Sn$_6$. Diffuse scattering appears along a frustrated wave vector $\textbf{q}_H=(\frac{1}{3},\frac{1}{3},\frac{1}{2})$ at temperatures far exceeding the charge order transition $T_{CO}=92~\mathrm{K}$, preempting long-range charge order with wave vectors along $\textbf{q}_{\bar{K}}=(\frac{1}{3},\frac{1}{3},\frac{1}{3})$. Using a combination of real space and reciprocal space analysis, we resolve the nature of the interactions between the primary out-of-plane Sc-Sn chain instability and the secondary strain-mediated distortion of the in-plane V kagome network. A minimal model of the diffuse scattering data reveals a high-temperature, short-ranged "zig-zag" phase of in-plane correlations that maps to a frustrated triangular lattice Ising model with antiferromagnetic interactions and provides a real-space understanding of the origin of frustrated charge order in this material., Comment: 7 pages, 4 figures
- Published
- 2024
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