New papers on Cosmology
54 new papers on cosmology in the last 7 days, within Space & cosmos. These are the 50 Pipette rates most worth reading, with the main result in the authors' own words.
The best of the week
JWST evidence for a sharp "Cosmic Daybreak" at z = 15
Taken literally, such a late transition from the Dark Ages to luminous galaxies is unlike the gradual Cosmic Dawn of standard LCDM, but does confirm a key prediction of Wave Dark Matter, DM, as a Bose-Einstein condensate.
PreprintBold claims, read criticallyClaims a big stepModel-Independent Measurement of Baryon Gas Fractions through Galaxy-Galaxy Lensing and the Kinematic Sunyaev-Zel'dovich Effect
We present model independent measurements of the radial gas fraction profile around galaxies, combining galaxy-galaxy lensing and kinematic Sunyaev-Zel'dovich (kSZ) effect.
PreprintConstraining Inflation with Little Red Dots
We find , and , improving on Planck by factors of , and .
PreprintLens Modeling and Cosmological Inference from an Impure Sample of Galaxy-Galaxy Strong Lenses
As a proof-of-concept, using simulated LSST measurements of the Einstein radii of a realistic and impure sample of photometric lens systems, i.e. those without spectroscopic confirmation, we find that the cosmological parameters , , and can be measured to a precision of , and respectively for a CDM cosmology.
PreprintHigh Resolution Grid-based Simulations of the Warm-Hot Intergalactic Medium
We find that ~23.4% of cosmic baryons reside in the WHIM phase (T = 10^5 - 10^7 K) at z = 0, significantly below the 40-50% found in earlier, lower-resolution simulations.
PreprintMerlin: Fast and flexible 3x2pt cosmology with simulation-based inference
We present Merlin, a simulation-based inference (SBI) pipeline to perform cosmological analyses of 3x2pt summary statistics: cosmic shear, galaxy clustering and the cross-correlation power spectra.
PreprintCode availableFrom starlight to dark matter: a stochastic interpolation approach to map dark matter from stellar density
In this paper, we explore a conditional generative model framework to map the dark matter profile of Milky Way-mass galaxies from stellar density profiles, more easily obtainable through large photometric imaging surveys.
PreprintCode availableTesting cosmic acceleration from thermogravity without vacuum energy
The resulting model, which can be thought of as a one parameter extension of , provides an improved fit relative to for the background dataset combinations considered, with improvements reaching and a maximum Bayesian preference of .
PreprintA note on oscillons: non-negligible metric fluctuations during preheating
Using the linearized Einstein constraints, we show that the suppression of the Bardeen potential, characteristic of slow-roll inflation, disappears during preheating: once the first slow-roll parameter becomes of order unity, the metric and inflaton fluctuations enter at the same perturbative order.
PreprintDark-matter relay for ultra-high-energy cosmic rays
Here we propose that dark matter can provide a mechanism to effectively transfer UHECRs from distant sources: dark-matter particles are boosted by UHECRs near the source and pass their momentum to baryons close to the observer.
PreprintFLUMEN: Neural Emulator of an Advanced Stochastic Weak Lensing Model
Building on this model, we develop FLUMEN, a conditional normalizing-flow emulator that predicts as a function of the source redshift up to and six cosmological parameters .
PreprintCode availableStatistical Fluctuations as Primordial Correlators in the CMB: Finite Chemical Potential Thermodynamics
Thermal energy-charge fluctuations thus provide a calculable source of realistic scalar correlations, while reservoir dynamics, equilibration, and later curvature-isocurvature transfer must come from a microscopic model.
PreprintDark matter self-annihilation as a hidden energy source in white dwarfs
We show that the majority of observed deviations in the WD MR relation can be accounted for by having SADM admixed with and , the thermal relic cross section.
PreprintMass-Dependent Dark Matter Deficit from Inelastic Scattering
We show that this mass dependence can arise from exothermic inelastic dark matter with strongly velocity-dependent scattering.
PreprintTangled : Planck CMB Constraints on Flash Reionization
In this work, we present the first Markov Chain Monte Carlo analysis of the flash reionization model fit to Planck cosmic microwave background temperature, polarization, and lensing data.
PreprintShape Degeneracies: the likely culprit for the differences between lens mass models of galaxy clusters
We conclude with three main takeaways: (i) Shape degeneracies are the likely cause of differences in the mass maps of cluster lenses recovered by different techniques.
PreprintHierArchical Wavelet Coefficients on the Sphere (HAWCS): the Scattering Transform on Spherical Maps
We introduce HAWCS, a healpy-based Python package for efficiently computing wavelet scattering transform coefficients from full-sky maps.
PreprintThe logotropic dark fluid as an energy diffusion in unimodular gravity
We show that the logotropic dark fluid, proposed as a single-fluid unification of dark matter and dark energy, is exactly dissipative unimodular gravity with pressureless matter and the logarithmic energy diffusion function .
PreprintSystematic Uncertainties and Their Impact on Gamma-Ray Searches for Dark Matter in Dwarf Galaxies
We find that adding an uncertainty of or 1.0 in quadrature weakens the median upper limits of a stacked analysis by factors of 1.4 or 3.2, respectively.
PreprintStatistics of large-scale structure from the transition probability of Lagrangian trajectories
Working purely in configuration space, we show that the two-point function can be formulated in terms of a transition probability describing the likely final position of a particle given its initial position.
PreprintNatural coordinates for constrained correlation functions: Partial autocorrelations and the geometry of positive power spectra
The partial autocorrelations thus provide natural coordinates on the admissible region, each varying independently in .
PreprintEntropy applications in cosmology: spacetime thermodynamics, holographic dark energy, entropic gravity and beyond - a review
In this review, we present a unified account of entropy in gravitational and cosmological contexts.
PreprintThe CAMELS-CROCODILE Simulation Suite: A New Cosmology--Astrophysics Playground for Machine Learning
We present CAMELS-CROCODILE, a suite of cosmological hydrodynamic simulations that extends the CAMELS framework with the \gadget{} smoothed particle hydrodynamics code and the Osaka feedback model.
PreprintJoint Model-independent Constraints on the Post-Newtonian Parameter and Cosmic Curvature from Galaxy-scale Strong Lensing, SNe Ia, BAO, and Cosmic Chronometers
Our results show that gamma PPN = 1.119 (+0.072/-0.072) and Omega k = 0.101 (+0.077/-0.076) at 68% confidence.
PreprintCross-Bispectrum Constraints from HI Intensity Mapping and Galaxy Surveys
By formulating the HI-HI-galaxy and HI-HI-shear cross-bispectra, we recover sensitivity to long-wavelength radial modes otherwise removed by foreground subtraction in HI maps, evaluating their detectability for HIRAX and Rubin-LSST.
PreprintGravitational-Susceptibility Dip Behind DESI's results: Addressing the Phantom Crossing by Local limit of Nonlocal Gravity
We show that the local limit of nonlocal gravity, a teleparallel extension of general relativity governed by a scalar function called gravitational susceptibility , offers a natural explanation.
PreprintConstraints on Axion-like Dark Matter from Cosmic Birefringence with a Polarization Array of Repeating Fast Radio Bursts
We find no compelling evidence for ALDM-induced PA oscillations in either the individual source analyses or the joint FRBPA analysis.
PreprintSound-Horizon-Independent Test of Cosmic Distance Duality Relation Using Artificial Neural Networks and Gaussian Processes
Our results show no significant deviation from the CDDR exceeding , and for the CC+BAO+DES-Dovekie combination it remains within over most of the redshift range.
PreprintThe Deep Learning Halo Definer: A Multimodal Framework for Halo Mass and Gas Fraction Inference on Galaxy Groups and Clusters
We introduce the Deep Learning Halo Definer (DLHD), a multimodal deep learning framework that simultaneously processes galaxy catalogues and X-ray imaging through the combination of a Deep Sets and a Convolutional Neural Network (CNN) to improve M_{halo} and f_{gas} estimation for galaxy groups and clusters.
PreprintA two-component profile of baryonic feedback: hydrostatic and diffuse gas
We introduce a physically motivated approach to modelling the gas distribution that decomposes it into an approximately hydrostatic inner component and a diffuse outer component.
PreprintBasis function expansions of the two-point correlation function and reconstruction of the cosmological distance scale
We show how to use these bases to measure the correlation function and estimate the reconstructed distance scale in a single step.
PreprintCosmic web Ly emission in a sample of overdense regions
We present a complete and homogeneous analysis of the Ly emission properties of the cosmic web at as a function of the overdensity of Ly emitters (LAEs) in the MUSE Ultra Deep Field (MUDF) and the MUSE Extremely Deep Field (MXDF).
PreprintRegular Cosmologies: Three Distinct Routes
We find that in all three prescriptions a monotonically decreasing core density gives an equation of state that never crosses , and thus the phantom behaviour suggested by DESI would require a density shell which a regular core does not have.
PreprintA novel phenomenological parametrization of dynamical dark energy via matter-gravity coupling
We develop a new parametrization for generic departures from the CDM model based on the Markov-Mukhanov action with non-minimal matter-gravity coupling.
PreprintNon-linear halo bias for accurate modelling of cosmic infrared background anisotropies
Our results demonstrate that accurately modelling non-linear halo clustering is essential not only to reproduce CIB anisotropies, but also to reliably recover the underlying galaxy-halo connection.
PreprintMulti-Stage and Multi-Field Inflation in Random Inflationary Landscapes
We find a substantial fraction of multi-stage inflationary trajectories in landscapes with field-space dimensions one, two, and three, and this fraction increases with dimensionality at fixed typical landscape curvature.
PreprintHunting Thermal Relics in the DESI DR1 Ly Forest
No significant evidence for additional radiation or a sterile component is found.
PreprintCode availableThe Lumina Project: Morphology of Ionized Bubbles and Neutral Islands
We analyze the geometry and physical properties of ionized bubbles and late-time neutral islands in the large-volume 500 Mpc radiation-hydrodynamics simulation Lumina.
PreprintExploring the influence of reionisation-era galaxies on their local intergalactic medium using the Sherwood-Relics simulations
Our results generally agree with observations claiming that there is a large-scale ionisation bias around [OIII] emitters, supporting the idea that their role is significant in shaping the properties of the IGM during reionisation.
PreprintGranular Structure and Local de Broglie Wavelength in Fuzzy Dark Matter Halos
These results provide a quantitative connection between density fluctuations, the local velocity field, and the core-halo morphology of FDM halos.
PreprintNoether Symmetry in a Non-Metricity Theory with a Boundary Term: Exact Solutions and Bayesian Cosmological Constraints
These results demonstrate that the model provides a viable alternative description of late-time cosmology.
PreprintTwo-rung ladder: from Tip of the Red Giant Branch and geometric anchors alone
We infer the Hubble constant from the ~400 Extragalactic Distance Database hosts with a tip of the red giant branch (TRGB) distance, calibrated on the geometric anchors of the Large Magellanic Cloud and NGC 4258.
Preprint21-cm Constraints on S-wave Dark Matter Annihilation with Subhalo-enhanced Effects
Our numerical results show that the projected HERA limit for the annihilation channel is stronger than the Leo~T bound within the dark matter mass range of , whereas the projected HERA limit for the annihilation channel is the strongest among the existing bounds for --.
PreprintExploring mutated hilltop inflation in gravity with latest CMB and DESI observations
We report that MHI can predict and is compatible with the latest CMB & DESI bound SPA+BK+DESI at CL.
PreprintAxio-Dilaton Dark Energy: A Dynamical Systems and Bayesian Inference Analysis
Finally, a joint likelihood analysis reveals that while the model successfully accounts for dark energy dynamics, it is only slightly statistically favoured over CDM by current observations.
PreprintThermal-acoustic fermionic dynamics and primordial perturbations in warm Yukawa inflation
Our results show that thermalized fermions provide an additional mechanism for modifying primordial perturbations and offer new insights into the role of particle production in warm inflationary cosmology.
PreprintThe Optical Expansion Scalar in Cosmological Perturbation Theory
We then derive the linear perturbative expression and angular power spectrum for in a flat FLRW universe with scalar perturbations.
PreprintWave-Optics Imprints of Warm Dark Matter Subhalos with Prompt Cusps on Strongly Lensed Gravitational Waves
A percent-level detection in a strongly lensed massive black-hole binary would therefore establish the presence of substructure on Fresnel scales without diagnosing its inner profile.
PreprintQuantum Tunneling and the Emergence of Classical Spacetime in Einstein-{\AE}ther Quantum Cosmology
Our results indicate a higher probability for the quantum birth of the Universe in a parameter regime characterized by larger values of , and fluid energy , together with a smaller value of .
PreprintDark Matter-Induced Stellar Oscillations in the de Broglie Regime
Focusing on solar oscillations, we find a signal far below current sensitivity, and estimate that other stars are similarly unlikely to provide observable signals.
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