Search

The disintegrating ultra-short period rocky exoplanet K2-22b periodically emits dusty clouds in a dynamically chaotic process resulting in a variable transit depth from 0-1.3%. The effluents that sublimate off the surface and condense out in space are probably representative of the formerly interior layers convectively transported to the molten surface. Transmission spectroscopy of these transiting clouds reveal spectral fingerprints of the interior composition of this rocky world. We used JWST's Mid-Infrared Instrument (MIRI) as a low-resolution slitless spectrograph to observe four predicted transit windows for K2-22b. For each observation, we extracted a transmission spectrum over the spectral range of 4.3-11.8 $\mu$m. We detect one transit at high significance and two at low significance. We find that the data 1) disfavor featureless, iron-dominated core material, 2) are consistent with some form of magnesium silicate minerals, likely from mantle material, and 3) show a distinct and unexpected feature at $\sim$5 $\mu$m. The unexpected feature, also seen weakly in the low-significance transits, is consistent with some gas features, possibly NO and/or CO$_2$. These findings warrant further study to improve the constraints on the composition of this disintegrating rocky world.

State-of-the-art JWST observations are unveiling unprecedented views into the atmospheres of substellar objects in the infrared, further highlighting the importance of clouds. Current forward models struggle to fit the silicate clouds absorption feature at ~$10\,\mu$m observed in substellar atmospheres. In the MSG model, we aim to couple the MARCS 1D radiative-convective equilibrium atmosphere model with the 1D kinetic, stationary, non-equilibrium, cloud formation model DRIFT, to create a new grid of self-consistent cloudy substellar atmosphere models with microphysical cloud formation. We aim to test if this new grid is able to reproduce the silicate cloud absorption feature at ~$10\,\mu$m. We model substellar atmospheres with effective temperatures in the range 1200-2500 K and with $\log(g)=4.0$. We compute atmospheric structures that self-consistently account for condensate cloud opacities based on microphysical properties. We present an algorithm based on control theory to help converge such self-consistent models. Synthetic atmosphere spectra are computed for each model to explore the observable impact of the cloud microphysics. We additionally explore the impact of choosing different nucleation species (TiO$_2$ or SiO) and the effect of less efficient atmospheric mixing on these spectra. The new MSG cloudy grid using TiO$_2$ nucleation shows spectra which are redder in the near-infrared compared to the currently known population of substellar atmospheres. We find the models with SiO nucleation, and models with reduced mixing efficiency are less red in the near-infrared. The grid is unable to reproduce the silicate features similar to those found in recent JWST observations and Spitzer archival data. We thoroughly discuss further work that may better approximate the impact of convection in cloud-forming regions and steps that may help resolve the silicate cloud feature., Comment: Accepted for publication in A&A

It has been shown that light speckle fluctuations provide a means for noninvasive measurements of cerebral blood flow index (CBFi). While conventional Diffuse Correlation Spectroscopy (DCS) provides marginal brain sensitivity for CBFi in adult humans, new techniques have recently emerged to improve diffuse light throughput and thus, brain sensitivity. Here we further optimize one such approach, interferometric diffusing wave spectroscopy (iDWS), with respect to number of independent channels, camera duty cycle and full well capacity, incident power, noise and artifact mitigation, and data processing. We build the system on a cart and define conditions for stable operation. We show pulsatile CBFi monitoring at 4-4.5 cm source-collector separation in adults with moderate pigmentation (Fitzpatrick 4). We also report preliminary clinical measurements in the Neuro Intensive Care Unit (Neuro ICU). These results push the boundaries of iDWS CBFi monitoring performance beyond previous reports., Comment: 12 pages, 15 figures, 4 tables

The DarkNESS (Dark Matter Nano-satellite Equipped with Skipper Sensors) mission aims to deploy a skipper-CCD CubeSat Observatory to search for dark matter (DM) from Low Earth Orbit. This mission will employ novel skipper-CCDs to investigate O(keV) X-rays from decaying DM, as well as electron recoils from strongly-interacting sub-GeV DM. The DarkNESS mission will be the first space deployment of skipper-CCDs, and the DarkNESS team is developing a skipper-CCD instrument that is compatible with the CubeSat platform. DarkNESS has recently progressed from laboratory validation to a Critical Design Review (CDR) phase, with a launch opportunity anticipated in late 2025. The implementation of the DarkNESS skipper-CCD payload on the CubeSat platform will pave the way for future demonstrators of space-based imagers for X-ray and single-electron counting applications.

The central star of the Helix Nebula, WD 2226$-$210 presents enigmatic hard X-ray emission and mid-IR excess. The latter has been attributed to a dusty disk or a cloud-like structure around WD 2226$-$210 formed from material of Kuiper Belt-like or comet-like objects in highly eccentric orbits. We present here a detailed analysis of multi-epoch Chandra and XMM-Newton X-ray observations of WD 2226$-$210, comparing these to previous Einstein and ROSAT data. The luminosity of the hard X-ray component of WD 2226$-$210 has remained basically constant in the decade from 1992 to 2002, with very subtle evidence for variability in timescales of hours. Under the assumption that the X-ray emission from WD 2226$-$210 is due to accretion of material, an accretion rate of $\dot{M}\approx10^{-10}$ M$_\odot$ yr$^{-1}$ is estimated. The origin of the material accreted by WD 2226$-$210 is uncertain, and can be attributed to the disk-like structure around it or to a sub-stellar donor companion. The accretion rate proposed for the continuous replenishment by bombardment of the mid-IR-emitting structure around WD 2226$-$210 cannot match that required by the X-ray emission., Comment: 8 pages, 3 figures, 3 tables; accepted to MNRAS

We investigate a shift in the critical temperature of rotating Bose-Einstein condensates mediated by the melting of the vortex lattice. Numerical simulations reveal that this temperature exhibits contrasting behavior depending on the system configuration: a negative shift occurs for fixed trap potentials due to the expansion of the condensate, while a positive shift is observed for fixed volumes, where vortex lattice rigidity suppresses thermal fluctuations. We introduce a vortex-energy model that captures the role of vortex interactions, the positional energy of the vortex lattice, as well as the phase transition and how the vortex lattice disappears. The findings provide insights into the thermodynamic properties of rotating condensates and the dynamics of vortex lattice melting, offering potential parallels with other quantum systems such as type-II superconductors.

In recent years, the fifth-generation (5G) mobile network has been developed worldwide to remarkably improve network performance and spectral efficiency. Very recently, reconfigurable intelligent surfaces (RISs) technology has emerged as an innovative solution for controlling the propagation medium of the forthcoming sixth-generation (6G) networks. Specifically, RIS takes advantage of the reflected rays on the propagation environment to redirect them to a desired target, improving wireless coverage. To further improve RIS performance, an interesting technique called synchronized transmission with advanced reconfigurable surfaces (STARS) has appeared to allow simultaneous transmission and reflection of intelligent omni-surfaces. With that in mind, this paper introduces an enhanced strategy for the network planning of 5G and beyond (B5G) mobile networks in dense urban scenarios focused on the city of Quito-Ecuador. The efficacy of RIS and its cutting-edge STARS concept is emphasized, providing useful insights into coverage, quality, and throughput results. In particular, this work considers the 3.5/28 GHz frequency bands, optimizing the radio network and anticipating their applicability in B5G networks. Finally, simulation results are also shown, which allow the identification of the benefits of STAR RIS in terms of coverage, signal quality, and data performance., Comment: 6 pages, 12 figures, 2024 IEEE 29th International Workshop on Computer Aided Modeling and Design of Communication Links and Networks (CAMAD), presented in Session 11: Federation of 6G Infrastructures and Experimentation Facilities in a Network of Networks, October 22th - 2024

The James Webb Space Telescope (JWST) has recently discovered a new population of objects at high redshift referred to as `Little Red Dots' (LRDs). Their nature currently remains elusive, despite their surprisingly high inferred number densities. This emerging population of red point-like sources is reshaping our view of the early Universe and may shed light on the formation of high-redshift supermassive black holes. Here we present a spectroscopically confirmed LRD CANUCS-LRD-z8.6 at $z_{\rm spec}=8.6319\pm 0.0005$ hosting an Active Galactic Nucleus (AGN), using JWST data. This source shows the typical spectral shape of an LRD (blue UV and red optical continuum, unresolved in JWST imaging), along with broad H$\beta$ line emission, detection of high-ionization emission lines (CIV, NIV]) and very high electron temperature indicative of the presence of AGN. This is also combined with a very low metallicity ($Z<0.1 Z_\odot$). The presence of all these diverse features in one source makes CANUCS-LRD-z8.6 unique. We show that the inferred black hole mass of CANUCS-LRD-z8.6 ($M_{\rm BH}=1.0^{+0.6}_{-0.4}\times 10^{8}\rm ~M_\odot$) strongly challenges current standard theoretical models and simulations of black hole formation, and forces us to adopt `ad hoc' prescriptions. Indeed if massive seeds, or light seeds with super-Eddington accretion, are considered, the observed BH mass of CANUCS-LRD-z8.6 at $z=8.6$ can be reproduced. Moreover, the black hole is over-massive compared to its host, relative to the local $M_{\rm BH}-M_*$ relations, pointing towards an earlier and faster evolution of the black hole compared to its host galaxy., Comment: 4 main figures; 8 supplementary figures; 5 supplementary tables

Hints of toponium might be incipient in LHC data, as given the vast numbers of t quarks produced, some survive on the exponential-decay tail long enough to fasten ttbar together. I here discuss a few differences between the standard Quantum Chromodynamics (QCD) binding (the ``glue'') and exotic short-range binding (the ``nail''). If the binding energy below threshold reaches the 3 GeV range the peak of the eta_t is distinct enough that a cross-section dip should be apparent in the line shape, should there only be one isolated resonance, but is filled by the excited QCD states adding about a pbarn to the cross section of ttbar production. Their effect for smaller binding energies is a tenuous increase in the cross section. A new-physics short-range interaction, on the other hand, yields a larger cross-section for equal binding energy (or hardly a visible bound state for similar cross section). This is due to its larger ttbar relative wavefunction at small distances. Finally, assuming that standard QCD plays out, I comment on what size of constraints on new-physics coefficients one can expect at given precision., Comment: Six pages in Elsevier double column format, ten plots. Improvements include: replacing Cornell potential by static NNLO pNRQCD one; replacing renormalization scale; updating numerics as needed

The financial sector is increasingly concerned with the physical risks of climate change, but economic and financial impact representations are still developing, particularly for chronic risks. Mexico's Central Bank conducted a comprehensive assessment using a suite of global models to evaluate both physical and transition risks. We present the analysis concerning with chronic physical risks, underlining innovations such as the use of a recent integrated assessment model that enables grid-cell level analysis and differentiates urban and non-urban areas, capturing the local effects of climate change more accurately. The model includes multiple damage functions and a probabilistic climate model for encompassing analyses and detailed economic impact insights. Under the Current Policies scenario, economic losses could exceed 35 percent of Mexico's GDP by 2100. Accounting for the urban heat island effect, losses could surpass 20 trillion (USD) in present value, over ten times Mexico's 2024 GDP. However, implementing a scenario aligned with the Paris Agreement significantly reduces these losses, showcasing the benefits of international mitigation efforts, though substantial residual impacts persist. This study emphasizes integrating chronic physical risks into financial evaluations, proposing new approaches, metrics, and methods that exploit detailed, spatially explicit measures to improve risk and loss estimation and facilitate communication., Comment: 19 pages, 7 figures

Operational data in next-generation networks offers a valuable resource for Mobile Network Operators to autonomously manage their systems and predict potential network issues. Machine Learning and Digital Twin can be applied to gain important insights for intelligent decision-making. This paper proposes a framework for Radio Frequency planning and failure detection using Digital Twin reducing the level of manual intervention. In this study, we propose a methodology for analyzing Radio Frequency issues as external interference employing clustering techniques in operational networks, and later incorporating this in the planning process. Simulation results demonstrate that the architecture proposed can improve planning operations through a data-aided anomaly detection strategy.

Artificial intelligence (AI) technologies (re-)shape modern life, driving innovation in a wide range of sectors. However, some AI systems have yielded unexpected or undesirable outcomes or have been used in questionable manners. As a result, there has been a surge in public and academic discussions about aspects that AI systems must fulfill to be considered trustworthy. In this paper, we synthesize existing conceptualizations of trustworthy AI along six requirements: 1) human agency and oversight, 2) fairness and non-discrimination, 3) transparency and explainability, 4) robustness and accuracy, 5) privacy and security, and 6) accountability. For each one, we provide a definition, describe how it can be established and evaluated, and discuss requirement-specific research challenges. Finally, we conclude this analysis by identifying overarching research challenges across the requirements with respect to 1) interdisciplinary research, 2) conceptual clarity, 3) context-dependency, 4) dynamics in evolving systems, and 5) investigations in real-world contexts. Thus, this paper synthesizes and consolidates a wide-ranging and active discussion currently taking place in various academic sub-communities and public forums. It aims to serve as a reference for a broad audience and as a basis for future research directions., Comment: Accepted in Frontiers in Big Data and AI, Research Topic: Towards Fair AI for Trustworthy Artificial Intelligence

We analyze the proton$\text{-}$box contribution to the hadronic light$\text{-}$by$\text{-}$light part of the muon's anomalous magnetic moment, which is the first reported baryonic contribution to this piece. We follow the quark$\text{-}$loop analysis, incorporating the relevant data$\text{-}$driven and lattice proton form factors. Although the heavy mass expansion would yield a contribution of $\mathcal{O}(10^{-10})$, the damping of the form factors in the regions where the kernel peaks, explains our finding $a_{\mu}^{\rm{p-box}}=1.82 (7)\times 10^{-12}$, two orders of magnitude smaller than the forthcoming uncertainty on the $a_{\mu}$ measurement and on its Standard Model prediction., Comment: 18 pages, 4 figures

Yttrium calcium aluminate, with the formula CaYAl3O7, has been extensively researched due to its remarkable luminescent properties when doped or co-doped. Additionally, it exhibits exceptional piezoelectric properties at high temperatures. However, the potential magnetic properties this material can acquire through doping or co-doping have largely gone unexplored until now. In this innovative study, we investigate the quantum magnetic characteristics of yttrium calcium aluminate particles doped with transition metals such as cobalt, iron, and nickel. Our magnetic measurements of hysteresis curves in the macroscopic regime reveal intriguing magnetic characteristics that have not been documented in the literature. Given the high applicability of this material in biological microelectromechanical systems, we conducted a detailed study to demonstrate these findings.

Understanding the cancellation of ultraviolet and infrared singularities in perturbative quantum field theory is of central importance for the development and automation of various theoretical tools that make accurate predictions for observables at high-energy colliders. The loop-tree duality aims to find an efficient solution by treating loop and tree-level contributions under the same foot to achieve a local cancellation of singularities at the integrand level, and thus avoiding dimensional regularisation. In this talk, we exploit the causal properties of vacuum amplitudes in the loop-tree duality representation to present different applications to physical processes at higher orders., Comment: 6 pages, 3 figures, conference in 42nd International Conference on High Energy Physics (ICHEP2024)

A theory of ordinal powers of the ideal $\mathfrak{g}_{\mathcal{S}}$ of $\mathcal{S}$-ghost morphisms is developed by introducing for every ordinal $\lambda$, the $\lambda$-th inductive power $\mathcal{J}^{(\lambda)}$ of an ideal $\mathcal{J}.$ The Generalized $\lambda$-Generating Hypothesis ($\lambda$-GGH) for an ideal $\mathcal J$ of an exact category $\mathcal{A}$ is the proposition that the $\lambda$-th inductive power ${\mathcal{J}}^{(\lambda)}$ is an object ideal. It is shown that under mild conditions every inductive power of a ghost ideal is an object-special preenveloping ideal. When $\lambda$ is infinite, the proof is based on an ideal version of Eklof's Lemma. When $\lambda$ is an infinite regular cardinal, the Generalized $\lambda$-Generating Hypothesis is established for the ghost ideal $\mathfrak{g}_{\mathcal{S}}$ for the case when $\mathcal A$ a locally $\lambda$-presentable Grothendieck category and $\mathcal{S}$ is a set of $\lambda$-presentable objects in $\mathcal A$ such that $^\perp (\mathcal{S}^\perp)$ contains a generating set for $\mathcal A.$ As a consequence of $\lambda$-GGH for the ghost ideal $\mathfrak{g}_{R\mbox{-}\mathrm{mod}}$ in the category of modules $R\mbox{-}\mathrm{Mod}$ over a ring, it is shown that if the class of pure projective left $R$-modules is closed under extensions, then every left FP-projective module is pure projective. A restricted version $n$-GGH($\mathfrak{g}(\mathbf{C}(R))$) for the ghost ideal in $\mathbf{C}(R))$ is also considered and it is shown that $n$-GGH($\mathfrak{g}(\mathbf{C}(R))$) holds for $R$ if and only if the $n$-th power of the ghost ideal in the derived category $\mathbf{D}(R)$ is zero if and only if the global dimension of $R$ is less than $n.$ If $R$ is coherent, then the Generating Hypothesis holds for $R$ if and only if $R$ is von Neumann regular.

The growing power of data science can play a crucial role in addressing social discrimination, necessitating nuanced understanding and effective mitigation strategies of potential biases. Data Science Looks At Discrimination (dsld) is an R and Python package designed to provide users with a comprehensive toolkit of statistical and graphical methods for assessing possible discrimination related to protected groups, such as race, gender, and age. Our software offers techniques for discrimination analysis by identifying and mitigating confounding variables, along with methods for reducing bias in predictive models. In educational settings, dsld offers instructors powerful tools to teach important statistical principles through motivating real world examples of discrimination analysis. The inclusion of an 80-page Quarto book further supports users, from statistics educators to legal professionals, in effectively applying these analytical tools to real world scenarios., Comment: To be submitted to the Journal of Statistics and Data Science Education

In recent years, black hole (BH) solutions with an integrable singularity have garnered significant attention as alternatives to regular black holes (RBH). In these models, similarly to RBHs, an object would not undergo spaghettification when approaching the radial origin. Instead of the potentially unstable de Sitter core present in RBHs, an integrable singularity emerges where the Ricci scalar diverges while its volume integral remains finite. However, the construction of both RBH solutions and BHs with an integrable singularity typically requires the inclusion of specific forms of matter in the energy-momentum tensor. We demonstrate that, from a geometric perspective in the absence of matter, vacuum solutions in Lovelock gravity in $d=2n+1$ dimensions can be represented as vacuum BHs with an integrable singularity in Einstein-Gauss-Bonnet theory for $d=5$ and in cubic gravity for $d=7$. Meanwhile, the vacuum solution in quartic gravity is described as a vacuum RBH with a nontrivial hyperboloidal cross-section. For all the aforementioned cases, we have determined the conditions that the parameters in the solutions must satisfy. Remarkably, in all discussed cases, there is no presence of an internal horizon near a potentially unstable de Sitter core.

We present results from data acquired by the SENSEI experiment at SNOLAB after a major upgrade in May 2023, which includes deploying 16 new sensors and replacing the copper trays that house the CCDs with a new light-tight design. We observe a single-electron event rate of $(1.39 \pm 0.11) \times 10^{-5}$ e$^-$/pix/day, corresponding to $(39.8 \pm 3.1)$ e$^-$/gram/day. This is an order-of-magnitude improvement compared to the previous lowest single-electron rate in a silicon detector and the lowest for any photon detector in the near-infrared-ultraviolet range. We use these data to obtain a 90% confidence level upper bound of $1.53 \times 10^{-5}$ e$^-$/pix/day and to set constraints on sub-GeV dark matter candidates that produce single-electron events. We hypothesize that the data taken at SNOLAB in the previous run, with an older tray design for the sensors, contained a larger rate of single-electron events due to light leaks. We test this hypothesis using data from the SENSEI detector located in the MINOS cavern at Fermilab.

We study an exactly solvable random walk model with long-range memory on arbitrary networks. The walker performs unbiased random steps to nearest-neighbor nodes and intermittently resets to previously visited nodes in a preferential way, such that the most visited nodes have proportionally a higher probability to be chosen for revisit. The occupation probability can be expressed as a sum over the eigenmodes of the standard random walk matrix of the network, where the amplitudes slowly decay as power-laws at large time, instead of exponentially. The stationary state is the same as in the absence of memory and detailed balance is fulfilled. However, the relaxation of the transient part becomes critically self-organized at late times, as it is dominated by a single power-law whose exponent depends on the second largest eigenvalue and on the resetting probability. We apply our findings to finite networks such as rings, complete graphs, Watts-Strogatz and Barab\'asi-Albert networks, and to Barbell and comb-like graphs. Our study could be of interest for modeling complex transport phenomena, such as human mobility, epidemic spreading, or animal foraging., Comment: 16 pages, 4 figures

The next generation of experiments for rare-event searches based on skipper Charge Coupled Devices (skipper-CCDs) presents new challenges for the sensor packaging and readout. Scaling the active mass and simultaneously reducing the experimental backgrounds in orders of magnitude requires a novel high-density silicon-based package that must be massively produced and tested. In this work, we present the design, fabrication, testing, and empirical signal model of a multi-channel silicon package. In addition, we outline the chosen specifications for the ongoing production of 1500 wafers that will add up to a 10 kg skipper-CCD array with 24000 readout channels., Comment: 11 pages, 14 figures, 2 tables

Future space observatories dedicated to direct imaging and spectroscopy of extra-solar planets will require ultra-low-noise detectors that are sensitive over a broad range of wavelengths. Silicon charge-coupled devices (CCDs), such as EMCCDs, Skipper CCDs, and Multi-Amplifier Sensing CCDs, have demonstrated the ability to detect and measure single photons from ultra-violet to near-infrared wavelengths, making them candidate technologies for this application. In this context, we study a relatively unexplored source of low-energy background coming from Cherenkov radiation produced by energetic charged particles traversing a silicon detector. In the intense radiation environment of space, energetic cosmic rays produce high-energy tracks and more extended halos of low-energy Cherenkov photons, which are detectable with ultra-low-noise detectors. We present a model of this effect that is calibrated to laboratory data, and we use this model to characterize the residual background rate for ultra-low noise silicon detectors in space. We find that the rate of cosmic-ray-induced Cherenkov photon production is comparable to other detector and astrophysical backgrounds that have previously been considered., Comment: SPIE Proceeding; 9 pages, 6 figures

We provide a methodology for decoupling the bulk gravitational field equations of braneworld black holes to suppress the bulk singularities. Thus, we provide a regular braneworld black hole setup. To achieve this, we apply a Minimal Geometric Deformation (MGD) with respect to a coupling constant $ \alpha $ to the $4D$ Minkowski spacetime embedded in an extra dimension. This results in a gravitational decoupling into a system $ \mathcal{A} $ with equations of motion of order $ \alpha^0 $ and a system $ \mathcal{B} $, related to the so-called Quasi-Einstein equations of order $ \alpha $. This methodology allows for the construction of a regular geometry everywhere. We outline the necessary constraints for eliminating singularities and provide a recipe for solving the equations of motion. Both the warp factor, the scalar field, and the potential obtained are smooth and free from Dirac delta singularities. A control parameter is introduced such that, in the limit $ b \to 0 $, the Randall-Sundrum (RS) setup is recovered, resulting in a transition from a thick brane to a thin brane. The asymptotic behavior of the curvature invariant $ \displaystyle \lim_{y \to \pm \infty} R_{5D}(r,y) $ is positive near the de Sitter core (for small $ r $), asymptotically negative for finite $ r > r_* $, and asymptotically flat at the $4D$ boundary as $ r \to \infty $. Although this work aims to suppress bulk singularities, it is expected that our methodology may be useful for future investigations related to the embedding of gravitational objects within other braneworld contexts., Comment: Accepted for publication in Fortschritte der Physik - Progress of Physics

We deploy the Hartree-Fock approximation for all-heavy quark hadrons, including quarkonium, baryons, tetraquarks, pentaquarks, dibaryons and up to the 12-body dibaryon-antidibaryon which completely fill the $1s$ orbital, in a unified manner, with the spinless LO Coulomb interaction and beyond. After treating the $c$ and $b$ quarks in various combinations, we delve a bit longer on $t$-quark bound states. We extend the negative result of Kuchiev, Flambaum and Shuryak on the 12-body topball to now include the NLO QCD potential. We find that none of the examined multitop states should have binding energy exceeding their width in the Standard Model. Additional new-physics interactions can then be constrained by experimental searches for these bound states, assuming they are not detected, at a level somewhat less stringent than standing HEFT bounds, but with different systematics., Comment: 39 pages, 7 figures, 16 tables

Population pressure is speeding the rate of deforestation in Sub-Saharan Africa, increasing the cost of biomass cooking fuel, which over 80 percent of the population relies upon. Higher energy input costs for meal preparation command a larger portion of household spending which in turn induces families to focus their diet on quick cooking staples. We use a field experiment in Zambia to investigate the impact of solar cook stoves on meal preparation choices and expenditures on biomass fuel. Participants kept a detailed food diary recording every ingredient and fuel source used in preparing every dish at every meal for every day during the six weeks of the experiment. This produces a data set of 93,606 ingredients used in the preparation of 30,314 dishes. While treated households used the solar stoves to prepare around 40 percent of their dishes, the solar stove treatment did not significantly increase measures of nutritional diversity nor did treated households increase the number of dishes per meal or reduce the number of meals they skipped. However, treated households significantly reduced the amount of time and money spent on obtaining fuel for cooking. These results suggest that solar stoves, while not changing a household's dietary composition, does relax cooking fuel constraints, allowing households to prepare more meals by reducing the share of household expenditure that goes to meal preparation.

The Seidov limit is a bound on the maximum latent heat that a presumed first-order phase transition of neutron-star matter can have before its excess energy density, not compensated by additional pressure, results in gravitational collapse. Because latent heat forces an apparent nonanalytic behaviour in plots correlating physical quantities (kinks in two-dimensional, ridges in three-dimensional ones), it can be constrained by data. As the onset of collapse depends on the intensity of gravity, testing for sudden derivative changes and, if they are large, breaching the Seidov limit would reward with two successive discoveries: such a phase transition (which could stem from hadron matter but also from a gravitational phase transition), and a modification of General Relativity (thus breaking the matter/gravity degeneracy). We illustrate the point with $f(R)=R+\alpha R^2$ metric gravity., Comment: 27 pages, 11 figures

We present the first quantum computation of a total decay rate in high-energy physics at second order in perturbative quantum field theory. This work underscores the confluence of two recent cutting-edge advances. On the one hand, the quantum integration algorithm Quantum Fourier Iterative Amplitude Estimation (QFIAE), which efficiently decomposes the target function into its Fourier series through a quantum neural network before quantumly integrating the corresponding Fourier components. On the other hand, causal unitary in the loop-tree duality (LTD), which exploits the causal properties of vacuum amplitudes in LTD to coherently generate all contributions with different numbers of final-state particles to a scattering or decay process, leading to singularity-free integrands that are well suited for Fourier decomposition. We test the performance of the quantum algorithm with benchmark decay rates in a quantum simulator and in quantum hardware, and find accurate theoretical predictions in both settings., Comment: 6 pages (5+1), 5 figures

Working with Resonance Chiral Theory, within the two resonance multiplets saturation scheme, we satisfy leading (and some subleading) chiral and asymptotic QCD constraints and accurately fit simultaneously the $\pi^{0},\eta,\eta^{\prime}$ transition form factors, for single and double virtuality. In the latter case, we supplement the few available measurements with lattice data to ensure a faithful description. Mainly due to the new results for the doubly virtual case, we improve over existing descriptions for the $\eta$ and $\eta^\prime$. Our evaluation of the corresponding pole contributions to the hadronic light-by-light piece of the muon $g-2$ read: $a_\mu^{\pi^{0}\text{-}\rm{pole}}=\left(61.9\pm0.6^{+2.4}_{-1.5}\right)\times10^{-11}$, $a_\mu^{\eta\text{-}\rm{pole}}=\left(15.2\pm0.5^{+1.1}_{-0.8}\right)\times10^{-11}$ and $a_\mu^{\eta^\prime\text{-}\rm{pole}}=\left(14.2\pm0.7^{+1.4}_{-0.9}\right)\times10^{-11}$, for a total of $a_\mu^{\pi^0+\eta+\eta^{\prime}\text{-}\rm{pole}}=\left(91.3\pm1.0^{+3.0}_{-1.9}\right)\times10^{-11}$, where the first and second errors are the statistical and systematic uncertainties, respectively., Comment: 49 pages, 8 figures. The correlations between the pseudo-data points from Lattice QCD were considered and the Global Analysis was changed accordingly in this version. Furthermore, the high energy behavior was analyzed in the whole spectrum of asymmetries between the single virtual and the double virtual case

We present a new family of regular black holes (RBH) in Pure Lovelock gravity, where the energy density is determined by the gravitational vacuum tension, which varies for each value of $n$ in each Lovelock case. Speculatively, our model may capture quantum effects through gravitational tension. In this way, a hypothetical analogy is drawn between the pair production ratio in the Schwinger effect and our energy density. A notable feature of our model is that the regular solution closely resembles the vacuum solution before reaching the event horizon. For odd $n$, the transverse geometry is spherical, with phase transitions occurring during evaporation, and the final state of this process is a remnant. For even $n$, the transverse geometry is non trivial and corresponds to a hyperboloid. In the case of $d=2n+1$ with even $n$, we find an RBH without a dS core and no inner horizon (whose presence has been recently debated in the literature due to the question of whether its presence is unstable or not), and no phase transitions. For $d > 2n + 1$ with even $n$, the RBH possesses both an event horizon and a cosmological horizon, also with no inner horizon present. The existence of the cosmological horizon arises without the usual requirement of a positive cosmological constant. From both numerical and analytical analysis, we deduce that as the event horizon expands and the cosmological horizon contracts, thermodynamic equilibrium is achieved in a remnant when the two horizons coincide., Comment: accepted for publication in JCAP

We prove that every Polish group admits a non-trivial topological group automorphism. This answers a question posed by Forte Shinko. As a consequence, we prove that there are no uniquely homogeneous Polish groups., Comment: The argument in the last paragraph of the proof of Theorem 1.1 is faulty. Concretely, when we extend a non-trivial automorphism of L to the whole group by fixing any element of a maximal independent subset Y of U, we redefine the automorphism for the elements of L that are generated by Y. We thank Forte Shinko for pointing out this mistake

We present galaxy MACS0416-Y1 at z$_{\rm{spec}} = 8.312$ as observed by the CAnadian NIRISS Unbiased Cluster Survey (CANUCS). MACS0416-Y1 has been shown to have extreme dust properties, thus, we study the physical properties and star formation histories of its resolved components. Overall, we find that MACS0416-Y1 is undergoing a star formation burst in three resolved clumps. The central clump is less massive compared to the other clumps and possibly formed in the merging process of the two larger clumps. Although the star formation history indicates an ongoing star formation burst, this gas-rich galaxy shows comparable star formation efficiency to cosmic noon galaxies. Using NIRSpec prism spectroscopy, we measure metallicity, $12 +\log\rm{(O/H)} = 7.76\pm0.03$ , ionisation parameter, $\log U = -2.48\pm0.03$, and electron temperature $\rm{T}_e = 18000\pm 4000 K $. The emission line ratios of the galaxy indicate an evolved Interstellar medium (ISM) similar to $z\sim2$ star-forming galaxies. Further, we find possible presence of ionisation from an active galactic nuclei (AGN) using emission line diagnostics, however, we do not detect broad line component in H$\beta$ emission line. As this gas-rich galaxy is undergoing a major merger, we hypothesise that the high dust temperature in MACS0416-Y1 is caused by the star formation burst or a possible narrow-line AGN.

In the late stages of accretion leading up to the formation of planetesimals, particles grew to pebbles the size of 1-mm to tens of cm. That is the same size range that dominates the present-day comet mass loss. Meteoroids that size cause visible meteors on Earth. Here, we hypothesize that the size distribution and the physical and chemical properties of young meteoroid streams still contain information about the conditions in the solar nebula during these late stages of accretion. From observations of 47 young meteor showers, we find that freshly ejected meteoroids from long-period comets tend to have low bulk density and are distributed with equal surface area per log-mass interval (magnitude distribution index chi ~ 1.85), suggesting gentle accretion conditions. Jupiter-family comets, on the other hand, mostly produce meteoroids twice as dense and distributed with a steeper chi ~ 2.15 or even chi ~ 2.5, which implies that those pebbles grew from particles fragmenting in a collisional cascade or by catastrophic collisions, respectively. Both comet populations contain an admixture of compact materials that are sometimes sodium-poor, but Jupiter-family comets show a higher percentage (~8% on average) than long-period comet showers (~4%), and a wider range. While there are exceptions in both groups, the implication is that most long-period comets formed under gentle particle growth conditions, possibly near the 30 AU edge of the Trans Neptunian Disk, while most Jupiter family comets formed closer to the Sun where pebbles reached or passed the fragmentation barrier. This is possible if the Scattered Disk represents all objects scattered by Neptune during its migration, while the present-day outer Oort cloud formed only during and after the Sun had moved away from sibling stars., Comment: 82 pages, 14 figures, 3 tables

An optimal sequential experimental design approach is developed to computationally characterize soft material properties at the high strain rates associated with bubble cavitation. The approach involves optimal design and model inference. The optimal design strategy maximizes the expected information gain in a Bayesian statistical setting to design experiments that provide the most informative cavitation data about unknown soft material properties. We infer constitutive models by characterizing the associated viscoelastic properties from measurements via a hybrid ensemble-based 4D-Var method (En4D-Var). The inertial microcavitation-based high strain-rate rheometry (IMR) method ([1]) simulates the bubble dynamics under laser-induced cavitation. We use experimental measurements to create synthetic data representing the viscoelastic behavior of stiff and soft polyacrylamide hydrogels under realistic uncertainties. The synthetic data are seeded with larger errors than state-of-the-art measurements yet match known material properties, reaching 1% relative error within 10 sequential designs (experiments). We discern between two seemingly equally plausible constitutive models, Neo-Hookean Kelvin--Voigt and quadratic Kelvin--Voigt, with a probability of correctness larger than 99% in the same number of experiments. This strategy discovers soft material properties, including discriminating between constitutive models and discerning their parameters, using only a few experiments.