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The time delay between multiple images of strongly lensed quasars has been used to infer the Hubble constant. The primary systematic uncertainty for time-delay cosmography is the mass-sheet transform (MST), which preserves the lensing observables while altering the inferred $H_0$. The TDCOSMO collaboration used velocity dispersion measurements of lensed quasars and lensed galaxies to infer that mass sheets are present, which decrease the inferred $H_0$ by 8$\%$. Here, we test the assumption that the density profiles of galaxy-galaxy and galaxy-quasar lenses are the same. We use a composite star-plus-dark-matter mass profile for the parent deflector population and model the selection function for galaxy-galaxy and galaxy-quasar lenses. We find that a power-law density profile with an MST is a good approximation to a two-component mass profile around the Einstein radius, but we find that galaxy-galaxy lenses have systematically higher mass-sheet components than galaxy-quasar lenses. For individual systems, $\lambda_\mathrm{int}$ correlates with the ratio of the half-light radius and Einstein radius of the lens. By propagating these results through the TDCOSMO methodology, we find that $H_0$ is lowered by a further $\sim$3\%. Using the velocity dispersions from \citet{slacs9} and our fiducial model for selection biases, we infer $H_0 = 66\pm4 \ \mathrm{(stat)} \pm 1 \ \mathrm{(model \ sys)} \pm 2 \ \mathrm{(measurement \ sys)} \ \mathrm{km} \ \mathrm{s}^{-1} \ \mathrm{Mpc}^{-1}$ for the TDCOSMO plus SLACS dataset. The first residual systematic error is due to plausible alternative choices in modeling the selection function, and the second is an estimate of the remaining systematic error in the measurement of velocity dispersions for SLACS lenses. Accurate time-delay cosmography requires precise velocity dispersion measurements and accurate calibration of selection biases.

One of the most challenging problems in the computational study of localization in quantum manybody systems is to capture the effects of rare events, which requires sampling over exponentially many disorder realizations. We implement an efficient procedure on a quantum processor, leveraging quantum parallelism, to efficiently sample over all disorder realizations. We observe localization without disorder in quantum many-body dynamics in one and two dimensions: perturbations do not diffuse even though both the generator of evolution and the initial states are fully translationally invariant. The disorder strength as well as its density can be readily tuned using the initial state. Furthermore, we demonstrate the versatility of our platform by measuring Renyi entropies. Our method could also be extended to higher moments of the physical observables and disorder learning.

Planets in compact multi-transiting systems tend to exhibit self-similarity with their neighbors, a phenomenon commonly called "peas-in-a-pod". Previous studies have identified that this self-similarity appears independently among super-Earths and sub-Neptunes orbiting the same star. In this study, we investigate whether the peas-in-a-pod phenomenon holds for planets in the radius gap between these two categories (located at $\sim$1.8$R_{\oplus}$). Employing the Kepler sample of planets in multi-transiting systems, we calculate the radius ratios between radius gap planets and their neighbors. We find that in systems in possession of a radius gap planet, there is a statistically significant deficit of planet pairs with radius ratios near unity, at the level of $3-4\sigma$. We find that neighbors to radius gap planets actually exhibit reverse size-ordering (that is, a larger inner planet is followed by an outer smaller planet) more often than they exhibit self-similarity. We go on to compare whether the period ratios between neighboring planets also differ, and find that radius gap planets are likelier to reside in mean motion resonance with neighbors, compared to non-gap planets (particularly in the 3:2 configuration). We explore the possibility that systems with a radius gap planet may be modified by a process other than photoevaporation or core-powered mass loss. The appearance in tandem of unusual size-ordering of gap planets in multi-planet systems, together with unusual spacing, furnishes potential supporting evidence in favor of giant impacts sculpting the radius distribution to some degree., Comment: 21 pages, 9 figures

Lattice gauge theories (LGTs) can be employed to understand a wide range of phenomena, from elementary particle scattering in high-energy physics to effective descriptions of many-body interactions in materials. Studying dynamical properties of emergent phases can be challenging as it requires solving many-body problems that are generally beyond perturbative limits. We investigate the dynamics of local excitations in a $\mathbb{Z}_2$ LGT using a two-dimensional lattice of superconducting qubits. We first construct a simple variational circuit which prepares low-energy states that have a large overlap with the ground state; then we create particles with local gates and simulate their quantum dynamics via a discretized time evolution. As the effective magnetic field is increased, our measurements show signatures of transitioning from deconfined to confined dynamics. For confined excitations, the magnetic field induces a tension in the string connecting them. Our method allows us to experimentally image string dynamics in a (2+1)D LGT from which we uncover two distinct regimes inside the confining phase: for weak confinement the string fluctuates strongly in the transverse direction, while for strong confinement transverse fluctuations are effectively frozen. In addition, we demonstrate a resonance condition at which dynamical string breaking is facilitated. Our LGT implementation on a quantum processor presents a novel set of techniques for investigating emergent particle and string dynamics.

In this article, we focus on the communication costs of three symmetric matrix computations: i) multiplying a matrix with its transpose, known as a symmetric rank-k update (SYRK) ii) adding the result of the multiplication of a matrix with the transpose of another matrix and the transpose of that result, known as a symmetric rank-2k update (SYR2K) iii) performing matrix multiplication with a symmetric input matrix (SYMM). All three computations appear in the Level 3 Basic Linear Algebra Subroutines (BLAS) and have wide use in applications involving symmetric matrices. We establish communication lower bounds for these kernels using sequential and distributed-memory parallel computational models, and we show that our bounds are tight by presenting communication-optimal algorithms for each setting. Our lower bound proofs rely on applying a geometric inequality for symmetric computations and analytically solving constrained nonlinear optimization problems. The symmetric matrix and its corresponding computations are accessed and performed according to a triangular block partitioning scheme in the optimal algorithms., Comment: 43 pages, 6 figures. To be published in ACM Transactions on Parallel Computing

The formation of planetary systems has historically been considered in isolation, decoupled from processes on galactic scales. Recent findings employing data from ESA's Gaia mission challenge this narrative, identifying trends in planet occurrence with galactic kinematics and stellar age. The findings indicate changes in planet occurrence over and above the predicted changes from metallicity variation within the Milky Way, so that changes to stellar metallicity alone (long understood to be deterministic in planet outcomes) cannot explain the trends entirely. The scope of potential factors influencing planet formation has grown progressively wider, with accompanying theoretical support for galactic-scale influences upon planet formation. In this manuscript, we investigate specifically how changes to the rate of Systems of Tightly-packed Inner Planets (STIPs) could manifest as a trend in planet occurrence with galactic height. We focus our study upon M dwarf planetary systems for two reasons: first, they host STIPs at high rates, and secondly, their longevity makes them useful probes for kinematic trends over Gyr. We consider two models for a varying STIP rate: one in which STIP likelihood is determined by stellar age alone, irrespective of galactic time, and another in which the STIP likelihood suddenly increased in recent galactic history. Both models, which impose a higher STIP likelihood among younger stars, produce a negative gradient in planet occurrence with increasing height from the galactic midplane. We find that a step function model in which STIP likelihood increased by a factor of several ~a few Gyr ago resembles an observed trend among FGK dwarfs. We consider plausible physical mechanisms that could mimic the hypothesized model, given known links between STIP occurrence and other stellar and planetary properties., Comment: 21 pages, 7 figures. Submitted to AJ

In visual decision making, high-level features, such as object categories, have a strong influence on choice. However, the impact of low-level features on behavior is less understood partly due to the high correlation between high- and low-level features in the stimuli presented (e.g., objects of the same category are more likely to share low-level features). To disentangle these effects, we propose a method that de-correlates low- and high-level visual properties in a novel set of stimuli. Our method uses two Convolutional Neural Networks (CNNs) as candidate models of the ventral visual stream: the CORnet-S that has high neural predictivity in high-level, IT-like responses and the VGG-16 that has high neural predictivity in low-level responses. Triplets (root, image1, image2) of stimuli are parametrized by the level of low- and high-level similarity of images extracted from the different layers. These stimuli are then used in a decision-making task where participants are tasked to choose the most similar-to-the-root image. We found that different networks show differing abilities to predict the effects of low-versus-high-level similarity: while CORnet-S outperforms VGG-16 in explaining human choices based on high-level similarity, VGG-16 outperforms CORnet-S in explaining human choices based on low-level similarity. Using Brain-Score, we observed that the behavioral prediction abilities of different layers of these networks qualitatively corresponded to their ability to explain neural activity at different levels of the visual hierarchy. In summary, our algorithm for stimulus set generation enables the study of how different representations in the visual stream affect high-level cognitive behaviors., Comment: Accepted at Workshop on Human-inspired Computer Vision @ ECCV 2024

Radial velocity (RV) follow-up is a critical complement of transiting exoplanet surveys like the Transiting Exoplanet Survey Satellite (TESS ), both for validating discoveries of exoplanets and measuring their masses. Stellar activity introduces challenges to interpreting these measurements because the noise from the host star, which is often correlated in time, can result in high RV uncertainty. A robust understanding of stellar activity and how its timescales interact with the observing cadence can optimize limited RV resources. For this reason, in the era of over-subscribed, high-precision RV measurements, folding stellar activity timescales into the scheduling of observation campaigns is ideal. We present gaspery, an open-source code implementation to enable the optimization of RV observing strategies. Gaspery employs a generalized formulation of the Fisher Information for RV time series that also incorporates information about stellar correlated noise. We show that the information contained in an observing strategy can be significantly affected by beat frequencies between the orbital period of the planet, the stellar rotation period, and the observation epochs. We investigate how the follow-up observing strategy will affect the resulting radial velocity uncertainty, as a function of stellar properties such as the spot decay timescale and rotation period. We then describe two example use cases for gaspery: 1) calculating the minimum number of observations to reach an uncertainty tolerance in a correlated noise regime and 2) finding an optimal strategy given a fixed observing budget. Finally, we outline a prescription for selecting an observing strategy that is generalizable to different targets., Comment: 19 pages, 7 figures, accepted for publication by AAS Journals

Quantum error correction provides a path to reach practical quantum computing by combining multiple physical qubits into a logical qubit, where the logical error rate is suppressed exponentially as more qubits are added. However, this exponential suppression only occurs if the physical error rate is below a critical threshold. In this work, we present two surface code memories operating below this threshold: a distance-7 code and a distance-5 code integrated with a real-time decoder. The logical error rate of our larger quantum memory is suppressed by a factor of $\Lambda$ = 2.14 $\pm$ 0.02 when increasing the code distance by two, culminating in a 101-qubit distance-7 code with 0.143% $\pm$ 0.003% error per cycle of error correction. This logical memory is also beyond break-even, exceeding its best physical qubit's lifetime by a factor of 2.4 $\pm$ 0.3. We maintain below-threshold performance when decoding in real time, achieving an average decoder latency of 63 $\mu$s at distance-5 up to a million cycles, with a cycle time of 1.1 $\mu$s. To probe the limits of our error-correction performance, we run repetition codes up to distance-29 and find that logical performance is limited by rare correlated error events occurring approximately once every hour, or 3 $\times$ 10$^9$ cycles. Our results present device performance that, if scaled, could realize the operational requirements of large scale fault-tolerant quantum algorithms., Comment: 10 pages, 4 figures, Supplementary Information

Looking up an unknown sign in an ASL dictionary can be difficult. Most ASL dictionaries are organized based on English glosses, despite the fact that (1) there is no convention for assigning English-based glosses to ASL signs; and (2) there is no 1-1 correspondence between ASL signs and English words. Furthermore, what if the user does not know either the meaning of the target sign or its possible English translation(s)? Some ASL dictionaries enable searching through specification of articulatory properties, such as handshapes, locations, movement properties, etc. However, this is a cumbersome process and does not always result in successful lookup. Here we describe a new system, publicly shared on the Web, to enable lookup of a video of an ASL sign (e.g., a webcam recording or a clip from a continuous signing video). The user submits a video for analysis and is presented with the five most likely sign matches, in decreasing order of likelihood, so that the user can confirm the selection and then be taken to our ASLLRP Sign Bank entry for that sign. Furthermore, this video lookup is also integrated into our newest version of SignStream(R) software to facilitate linguistic annotation of ASL video data, enabling the user to directly look up a sign in the video being annotated, and, upon confirmation of the match, to directly enter into the annotation the gloss and features of that sign, greatly increasing the efficiency and consistency of linguistic annotations of ASL video data., Comment: 11 pages, 10 figures

We report the discovery and validation of HD 21520 b, a transiting planet found with TESS and orbiting a bright G dwarf (V=9.2, $T_{eff} = 5871 \pm 62$ K, $R_{\star} = 1.04\pm 0.02\, R_{\odot}$). HD 21520 b was originally alerted as a system (TOI-4320) consisting of two planet candidates with periods of 703.6 and 46.4 days. However, our analysis supports instead a single-planet system with an orbital period of $25.1292\pm0.0001$ days and radius of $2.70 \pm 0.09\, R_{\oplus}$. Three full transits in sectors 4, 30 and 31 match this period and have transit depths and durations in agreement with each other, as does a partial transit in sector 3. We also observe transits using CHEOPS and LCOGT. SOAR and Gemini high-resolution imaging do not indicate the presence of any nearby companions, and MINERVA-Australis and CORALIE radial velocities rule out an on-target spectroscopic binary. Additionally, we use ESPRESSO radial velocities to obtain a tentative mass measurement of $7.9^{+3.2}_{-3.0}\, M_{\oplus}$, with a 3-$\sigma$ upper limit of 17.7 $M_{\oplus}$. Due to the bright nature of its host and likely significant gas envelope of the planet, HD 21520 b is a promising candidate for further mass measurements and for atmospheric characterization., Comment: Submitted to MNRAS

Understanding how interacting particles approach thermal equilibrium is a major challenge of quantum simulators. Unlocking the full potential of such systems toward this goal requires flexible initial state preparation, precise time evolution, and extensive probes for final state characterization. We present a quantum simulator comprising 69 superconducting qubits which supports both universal quantum gates and high-fidelity analog evolution, with performance beyond the reach of classical simulation in cross-entropy benchmarking experiments. Emulating a two-dimensional (2D) XY quantum magnet, we leverage a wide range of measurement techniques to study quantum states after ramps from an antiferromagnetic initial state. We observe signatures of the classical Kosterlitz-Thouless phase transition, as well as strong deviations from Kibble-Zurek scaling predictions attributed to the interplay between quantum and classical coarsening of the correlated domains. This interpretation is corroborated by injecting variable energy density into the initial state, which enables studying the effects of the eigenstate thermalization hypothesis (ETH) in targeted parts of the eigenspectrum. Finally, we digitally prepare the system in pairwise-entangled dimer states and image the transport of energy and vorticity during thermalization. These results establish the efficacy of superconducting analog-digital quantum processors for preparing states across many-body spectra and unveiling their thermalization dynamics.

Widely deployed large language models (LLMs) can produce convincing yet incorrect outputs, potentially misleading users who may rely on them as if they were correct. To reduce such overreliance, there have been calls for LLMs to communicate their uncertainty to end users. However, there has been little empirical work examining how users perceive and act upon LLMs' expressions of uncertainty. We explore this question through a large-scale, pre-registered, human-subject experiment (N=404) in which participants answer medical questions with or without access to responses from a fictional LLM-infused search engine. Using both behavioral and self-reported measures, we examine how different natural language expressions of uncertainty impact participants' reliance, trust, and overall task performance. We find that first-person expressions (e.g., "I'm not sure, but...") decrease participants' confidence in the system and tendency to agree with the system's answers, while increasing participants' accuracy. An exploratory analysis suggests that this increase can be attributed to reduced (but not fully eliminated) overreliance on incorrect answers. While we observe similar effects for uncertainty expressed from a general perspective (e.g., "It's not clear, but..."), these effects are weaker and not statistically significant. Our findings suggest that using natural language expressions of uncertainty may be an effective approach for reducing overreliance on LLMs, but that the precise language used matters. This highlights the importance of user testing before deploying LLMs at scale., Comment: Accepted to FAccT 2024. This version includes the appendix

The sample of host stars with multiple transiting planets has illuminated the orbital architectures of exoplanetary systems. These architectures may be shaped mostly by formation conditions, be continually sculpted by ongoing dynamical processes, or both. As more studies place planet occurrence within a galactic context, evidence has emerged for variable planet multiplicity over time. In this manuscript, we investigate the use of transit multiplicity as a tool to constrain longer-timescale (>1 Gyr) dynamical sculpting. First, with a suite of injection-and-recovery tests, we quantify sensitivity to sculpting laws across different regimes. We employ a forward modeling framework in which we generate synthetic planetary systems, according to a prescribed sculpting speed and timescale, around the FGK dwarfs studied by the Kepler Mission. Some sculpting scenarios are hypothetically detectable in the Kepler sample, while others can be disfavored from Kepler transit statistics alone. Secondly, we apply our analysis to reverse-engineer the sculpting laws consistent with the true yield from Kepler. We confirm the present-day fraction of host stars containing dynamically cool "systems with tightly-packed inner planets" (STIPs) is 4-13%. A variety of Gyr-timescale sculpting laws successfully predict the transit multiplicity of the Kepler sample, but none of these laws succeeds in also producing a detectable trend with transit multiplicity and stellar age. An improvement to measured stellar age precision may help uncover such a sculpting law, but nevertheless reflects limitations in transit multiplicity as an observable. Therefore other phenomena, apart from Gyr-timescale dynamical sculpting, may be required to explain the Kepler yield.

Stellar age measurements are fundamental to understanding a wide range of astronomical processes, including galactic dynamics, stellar evolution, and planetary system formation. However, extracting age information from Main Sequence stars is complicated, with techniques often relying on age proxies in the absence of direct measurements. The Gaia data releases have enabled detailed studies of the dynamical properties of stars within the Milky Way, offering new opportunities to understand the relationship between stellar age and dynamics. In this study, we leverage high-precision astrometric data from Gaia DR3 to construct a stellar age prediction model based only on stellar dynamical properties; namely, the vertical action. We calibrate two distinct, hierarchical stellar age--vertical action relations, first employing asteroseismic ages for red giant branch stars, then isochrone ages for main-sequence turn-off stars. We describe a framework called "zoomies" based on this calibration, by which we can infer ages for any star given its vertical action. This tool is open-source and intended for community use. We compare dynamical age estimates from "zoomies" with ages derived from other techniques for a sample of open clusters and main-sequence stars with asteroseismic age measurements. We also compare dynamical age estimates for stellar samples from the Kepler, K2, and TESS exoplanet transit surveys. While dynamical age relations are associated with large uncertainty, they are generally mass-independent and depend on homogeneously measured astrometric data. These age predictions are uniquely useful for large-scale demographic investigations, especially in disentangling the relationship between planet occurrence, metallicity, and age for low-mass stars., Comment: 23 pages, 12 figures, 2 tables. Submitted to AAS Journals

Symmetric Nonnegative Matrix Factorization (SymNMF) is a technique in data analysis and machine learning that approximates a symmetric matrix with a product of a nonnegative, low-rank matrix and its transpose. To design faster and more scalable algorithms for SymNMF we develop two randomized algorithms for its computation. The first algorithm uses randomized matrix sketching to compute an initial low-rank input matrix and proceeds to use this input to rapidly compute a SymNMF. The second algorithm uses randomized leverage score sampling to approximately solve constrained least squares problems. Many successful methods for SymNMF rely on (approximately) solving sequences of constrained least squares problems. We prove theoretically that leverage score sampling can approximately solve nonnegative least squares problems to a chosen accuracy with high probability. Finally we demonstrate that both methods work well in practice by applying them to graph clustering tasks on large real world data sets. These experiments show that our methods approximately maintain solution quality and achieve significant speed ups for both large dense and large sparse problems.

The stochastic simulation algorithm (SSA) and the corresponding Monte Carlo (MC) method are among the most common approaches for studying stochastic processes. They rely on knowledge of interevent probability density functions (PDFs) and on information about dependencies between all possible events. Analytical representations of a PDF are difficult to specify in advance, in many real life applications. Knowing the shapes of PDFs, and using experimental data, different optimization schemes can be applied in order to evaluate probability density functions and, therefore, the properties of the studied system. Such methods, however, are computationally demanding, and often not feasible. We show that, in the case where experimentally accessed properties are directly related to the frequencies of events involved, it may be possible to replace the heavy Monte Carlo core of optimization schemes with an analytical solution. Such a replacement not only provides a more accurate estimation of the properties of the process, but also reduces the simulation time by a factor of order of the sample size (at least $\approx 10^4$). The proposed analytical approach is valid for any choice of PDF. The accuracy, computational efficiency, and advantages of the method over MC procedures are demonstrated in the exactly solvable case and in the evaluation of branching fractions in controlled radical polymerization (CRP) of acrylic monomers. This polymerization can be modeled by a constrained stochastic process. Constrained systems are quite common, and this makes the method useful for various applications.

M dwarf stars comprise 70-80% of the galaxy's stars and host most of its rocky planets. They also importantly differ from Sunlike stars in that they are "active" for billions of years or more: rotating quickly, flaring often, and emitting large amounts of UV and X-ray light. The effects of stellar activity upon both photometry and spectroscopy make their exoplanets more difficult to detect, and M dwarfs exhibit this behavior for thousands of times longer than a typical Sunlike star. While activity signals such as flaring and stellar rotation can be more readily modeled or removed from photometry, the contribution of unresolved stellar activity to transit sensitivity is harder to quantify. In this paper, we investigate the difference in the detectability of planetary transits around a sample of M dwarfs observed by NASA's TESS Mission, characterized by a common stellar radius, effective temperature, and TESS magnitude. Our sample is classified as either "active" or "inactive" based upon the presence of H$\alpha$ in emission. After removing the more readily identifiable signatures of activity: stellar rotation and large flares, we perform an injection-and-recovery analysis of transits for each star. We extract detection sensitivity as a function of planetary radius and orbital period for each star in the sample. Then, we produce averaged sensitivity maps for the "active" stars and the "inactive" stars, for the sake of comparison. We quantify the extent to which signal-to-noise is degraded for transit detection, when comparing an active star to an inactive star of the same temperature and apparent brightness. We aim for these sensitivity maps to be useful to the exoplanet community in future M dwarf occurrence rate studies., Comment: 10 pages, 6 figures. Submitted to the Astronomical Journal

This paper introduces a no-code, machine-readable documentation framework for open datasets, with a focus on responsible AI (RAI) considerations. The framework aims to improve comprehensibility, and usability of open datasets, facilitating easier discovery and use, better understanding of content and context, and evaluation of dataset quality and accuracy. The proposed framework is designed to streamline the evaluation of datasets, helping researchers, data scientists, and other open data users quickly identify datasets that meet their needs and organizational policies or regulations. The paper also discusses the implementation of the framework and provides recommendations to maximize its potential. The framework is expected to enhance the quality and reliability of data used in research and decision-making, fostering the development of more responsible and trustworthy AI systems.

Previous work has established the enhanced occurrence of compact systems of multiple small exoplanets around metal-poor stars. Understanding the origin of this effect in the planet formation process is a topic of ongoing research. Here we consider the radii of planets residing in systems of multiple transiting planets, compared to those residing in single-transiting systems, with a particular focus on late-type host stars. We investigate whether the two radius distributions are consistent with being drawn from the same underlying planetary population. We construct a planetary sample of 290 planets around late K and M dwarfs containing 149 planets from single-transiting planetary systems and 141 planets from multi-transiting compact multiple planetary systems (54 compact multiples). We performed a two-sample Kolmogorov-Smirnov test, Mann-Whitney U test, and Anderson-Darling k-sampling test on the radius distributions of our two samples. We find statistical evidence (p < 0.0026) that planets in compact multiple systems are larger, on average, than their single-transiting counterparts for planets with $R_p <$ 6 R$_\oplus$. We determine that the offset cannot be explained by detection bias. We investigate whether this effect could be explained via more efficient outgassing of a secondary atmosphere in compact multiple systems due to the stress and strain forces of interplanetary tides on planetary interiors. We find that this effect is insufficient to explain our observations without significant enrichment in H$_2$O compared to Earth-like bulk composition., Comment: 18 pages, 9 figures, 18 tables, published in AJ (updating to published version)

We present a measurement of the Hubble Constant $H_0$ using the gravitational wave event GW190412, an asymmetric binary black hole merger detected by LIGO/Virgo, as a dark standard siren. This event does not have an electromagnetic counterpart, so we use the statistical standard siren method and marginalize over potential host galaxies from the Dark Energy Spectroscopic Instrument (DESI) survey. GW190412 is well-localized to 12 deg$^2$ (90% credible interval), so it is promising for a dark siren analysis. The dark siren value for $H_0=85.4_{-33.9}^{+29.1}$ km/s/Mpc, with a posterior shape that is consistent with redshift overdensities. When combined with the bright standard siren measurement from GW170817 we recover $H_0=77.96_{-5.03}^{+23.0}$ km/s/Mpc, consistent with both early and late-time Universe measurements of $H_0$. This work represents the first standard siren analysis performed with DESI data, and includes the most complete spectroscopic sample used in a dark siren analysis to date., Comment: Submitted to RNAAS

For temperate exoplanets orbiting M dwarf hosts, the proximity of the habitable zone to the star necessitates careful consideration of tidal effects. Spin synchronization of the planetary orbital period and rotation period is a common assumption for habitable zone planets across the entire M spectral type. This predicted tidal locking has important implications for conditions on the surface. In this manuscript, we investigate the plausibility of capture into Cassini State 2 for a known sample of 280 multiplanet systems orbiting M dwarf hosts. This resonance of the spin precession and orbital precession frequencies is capable of exciting planets into stable nonzero rotational obliquities. A large axial tilt resulting from this predicted resonance capture can preclude synchronous rotation, inducing some version of "day" and "night." Considering each planetary pair and estimating the spin and orbital precession frequencies, we report that 75% of detected planets orbiting M dwarfs may be plausibly excited to a high obliquity over long timescales. This is consistent with similar findings for planets orbiting close-in to FGK dwarfs. However, it is only for M dwarf planets that the parameter space relevant for capture into Cassini State 2 overlaps with the stellar habitable zone. This effect is strongest for host stars with effective temperatures $T_{eff}<3000$ K, where more than half of planets with $T_{eq}<400$ K could possess non-zero obliquity due to residence in Cassini State 2. This overlap renders the potential capture into Cassini States extremely relevant to understanding the galaxy's most common temperate planets., Comment: Submitted to ApJ; 13 pages, 8 figures

The $\Lambda$CDM paradigm successfully explains the large-scale structure of the Universe, but is less well constrained on sub-galactic scales. Gravitational lens modelling has been used to measure the imprints of dark substructures on lensed arcs, testing the small-scale predictions of $\Lambda$CDM. However, the methods required for these tests are subject to degeneracies among the lens mass model and the source light profile. We present a case study of the unique compound gravitational lens SDSSJ0946+1006, wherein a dark, massive substructure has been detected, whose reported high concentration would be unlikely in a $\Lambda$CDM universe. For the first time, we model the first two background sources in both I- and U-band HST imaging, as well as VLT-MUSE emission line data for the most distant source. We recover a lensing perturber at a $5.9\sigma$ confidence level with mass $\log_{10}(M_\mathrm{sub}/M_{\odot})=9.2^{+0.4}_{-0.1}$ and concentration $\log_{10}c=2.4^{+0.5}_{-0.3}$. The concentration is more consistent with CDM subhalos than previously reported, and the mass is compatible with that of a dwarf satellite galaxy whose flux is undetectable in the data at the location of the perturber. A wandering black hole with mass $\log_{10}(M_\mathrm{BH}/M_{\odot})=8.9^{+0.2}_{-0.1}$ is a viable alternative model. We systematically investigate alternative assumptions about the complexity of the mass distribution and source reconstruction; in all cases the subhalo is detected at around the $\geq5\sigma$ level. However, the detection significance can be altered substantially (up to $11.3\sigma$) by alternative choices for the source regularisation scheme., Comment: 24 pages, 16 figures, 5 appendices