Tootfinder

Dwarf diversity in $\Lambda$CDM with baryons
Akaxia Cruz, Alyson Brooks, Mariangela Lisanti, Annika H. G. Peter, Robel Geda, Thomas Quinn, Michael Tremmel, Ferah Munshi, Ben Keller, James Wadsley
https://arxiv.org/abs/2510.11800

Dwarf diversity in $Λ$CDM with baryons
Observed rotation curves of dwarf galaxies exhibit significant diversity at fixed halo mass, challenging galaxy formation within the Cold Dark Matter (CDM) model. Previous cosmological galaxy formation simulations with baryonic physics fail to reproduce the full diversity of rotation curves, suggesting either that there is a flaw in baryonic feedback models, or that an alternative to CDM must be invoked. In this work, we use the Marvelous Massive Dwarf zoom-in simulations, a suite of high-resol…

Probing departures from $\Lambda$CDM by late-time datasets
Himanshu Chaudhary, Vipin Kumar Sharma, Salvatore Capozziello, G. Mustafa
https://arxiv.org/abs/2510.08339 https://

Probing departures from $Λ$CDM by late-time datasets
Observational data play a pivotal role in identifying cosmological models that are both theoretically consistent and empirically viable. In this work, we investigate whether the standard $Λ$CDM model exhibits significant departure with current late time datasets, including Cosmic Chronometers, Baryon Acoustic Oscillations from DESI DR2, and various Type Ia supernova compilations (Pantheon$^+$, DES-SN5Y, Union3). We analyze several dynamical dark energy models, including $ω$CDM, o$ω$CDM, $ω_…

F5 vulnerability highlights weak points in DHS’s CDM program
https://cyberscoop.com/f5-vulnerability-highlights-weak-points-in-dhss-cdm-program/#:~:text=F5 vulner…

F5 vulnerability highlights weak points in DHS’s CDM program
The Continuous Diagnostics and Mitigation program is oft-praised, but there are areas where it doesn’t yet excel, as a recent CISA emergency directive shows.

Investigating the $w$CDM Model with Latest DESI BAO Observations
Manisg Yadav, Archana Dixit, M. S. Barak, Anirudh Pradhan
https://arxiv.org/abs/2510.09074 https://

Investigating the $w$CDM Model with Latest DESI BAO Observations
In this study, we explore the impact of various combinations of CMB-independent datasets, including the recent DESI BAO measurements, on the equation of state (EoS) of dark energy and other cosmological parameters within the framework of the dynamical dark energy model ($w$CDM). Assuming a constant EoS parameter for dark energy, we derive constraints on the free parameters of the model using observational datasets such as DESI BAO, BBN, Observational Hubble Data (OHD), and Pantheon Plus (SN$^+$…

Is the $\Lambda$CDM Model in Crisis?
Himanshu Chaudhary, Salvatore Capozziello, Subhrat Praharaj, Shibesh Kumar Jas Pacif, G. Mustafa
https://arxiv.org/abs/2509.17124 https://…

Is the $Λ$CDM Model in Crisis?
We present strong evidence for dynamical dark energy challenging the $Λ$CDM model. Several dark energy models are explored, including $ω_0ω_a$CDM, logarithmic, Exponential, JBP, and BA, along with non-flat cosmologies accounting for potential spatial curvature. Our analysis supports a flat Universe ($Ω_k \approx 0$). Using the Metropolis-Hastings MCMC algorithm, we analyze data from BAO of DESI DR2, Type Ia Supernovae, and CMB to constrain model parameters. We find strong evidence that $ω\…

Matching JWST UV Luminosity Functions with Refined $\Lambda$CDM Halo Models
Saeed Fakhry, Maryam Shiravand, Antonino Del Popolo
https://arxiv.org/abs/2510.04709 https://

Matching JWST UV Luminosity Functions with Refined $Λ$CDM Halo Models
The James Webb Space Telescope (JWST) has unveiled a population of unexpectedly massive and luminous galaxies at redshifts $z \gtrsim 7$, posing a significant challenge to the standard $Λ$CDM cosmological paradigm. In this work, we address the tension between early JWST observations of luminous high-redshift galaxies and predictions of the standard $Λ$CDM model by revisiting the physics of dark matter halo formation. Employing refined halo mass functions derived by Del Popolo \textit{et al.} …

Everyone wants something better than $\Lambda$CDM
Michael S. Turner
https://arxiv.org/abs/2510.05483 https://arxiv.org/pdf/2510.05483

Everyone wants something better than $Λ$CDM
The current cosmological paradigm, $Λ$CDM, is characterized its expansive description of the history of the Universe, its deep connections to particle physics and the large amounts of data that support it. Nonetheless, $Λ$CDM's critics argue that it has been falsified or must be discarded for various reasons. Critics and boosters alike do agree on one thing: it is the not the final cosmological theory and they are anxious to see it replaced by something better! I review the status of $Λ$CDM,…

Alleviating the $H_0$ tension through new interacting dark energy model in light of DESI DR2
Yi-Min Zhang, Tian-Nuo Li, Guo-Hong Du, Sheng-Han Zhou, Li-Yang Gao, Jing-Fei Zhang, Xin Zhang
https://arxiv.org/abs/2510.12627

Alleviating the $H_0$ tension through new interacting dark energy model in light of DESI DR2
The $H_0$ tension has become one of the most significant challenges in modern cosmology. The recent DESI DR2 data has shown a significant preference for dynamical dark energy, yet this has further exacerbated the $H_0$ tension. In this work, we explore the potential of new interacting dark energy models ($\widetildeΛ$CDM and $e\widetildeΛ$CDM) to alleviate the $H_0$ tension. We perform observational constraints using the latest baryon acoustic oscillation data from DESI DR2, cosmic microwave …

Analysis of the plane of satellites around Milky Way-like galaxies in $\Lambda$CDM cosmology
Xinghai Zhao, Guobao Tang, Paola Gonzalez, Grant J. Mathews, Lara Arielle Phillips
https://arxiv.org/abs/2510.02518

Analysis of the plane of satellites around Milky Way-like galaxies in $Λ$CDM cosmology
It has been suggested that the Plane of Satellites (PoS) phenomenon may imply a tension with current $Λ$CDM cosmology since a Milky-Way (MW)-like PoS is very rare in simulations. In this study, we analyze a large sample of satellite systems of MW-like galaxies in the IllustrisTNG simulations. We analyze their spatial aspect ratio, orbital pole dispersion, Gini coefficient, radial distribution, and bulk satellite velocity relative to the host galaxy. These are compared to the observed Milky~Way…

Empirical Validation: Investigating the $\Lambda_s $CDM Model with new DESI BAO Observations
Manish Yadav, Archana Dixit, Anirudh Pradhan, M S Barak
https://arxiv.org/abs/2509.26049

Empirical Validation: Investigating the $Λ_s $CDM Model with new DESI BAO Observations
The $Λ$CDM model has long served as the cornerstone of modern cosmology, offering an elegant and successful framework for interpreting a wide range of cosmological observations. However, the rise of high-precision datasets has revealed statistically significant tensions, most notably the Hubble tension and the $S_8$ discrepancy, which challenge the completeness of this standard model. In this context, we explore the $Λ_{\rm s}$CDM model-an extension of $Λ$CDM featuring a single additional pa…

Updated observational constraints on $\phi$CDM dynamical dark energy cosmological models
Chan-Gyung Park, Bharat Ratra
https://arxiv.org/abs/2509.25812 https://

Updated observational constraints on $ϕ$CDM dynamical dark energy cosmological models
We present updated observational constraints on the spatially flat $ϕ$CDM model, where dark energy is described by a minimally coupled scalar field $ϕ$ with an inverse power-law potential $V=V_0 ϕ^{-α}$. Using Planck 2018 CMB temperature, polarization (P18), and lensing power spectra (lensing), along with a compilation of non-CMB data including baryon acoustic oscillation, type Ia supernova, Hubble parameter, and growth rate measurements, we constrain $ϕ$CDM and $ϕ$CDM+$A_L$ models where …

Seed models in scalar field cosmology
I. V. Fomin
https://arxiv.org/abs/2510.06724 https://arxiv.org/pdf/2510.06724…

Seed models in scalar field cosmology
The correspondence of single-field cosmological models based on Einstein gravity to modern observational data is considered. A method is proposed to determine possible types of dynamics based on extreme values of the scalar field. It is shown that within the framework of this approach, it is possible to obtain a limited class of known inflationary models at early times. It is also shown that on large times the proposed approach leads to the $Λ$CDM--model in order to describe the dynamics of th…

On the Frequency of Multiple Galaxy Mergers in $\Lambda$CDM Cosmological Simulations
Jonathan Mack, Shy Genel
https://arxiv.org/abs/2510.03525 https://arxi…

On the Frequency of Multiple Galaxy Mergers in $Λ$CDM Cosmological Simulations
Mergers are believed to play a pivotal role in galaxy evolution, and measuring the galaxy merger fraction is a longstanding goal of both observational and theoretical studies. In this work, we extend the consideration of the merger fraction from the standard measure of binary mergers, namely those comprising two merging galaxies, to multiple mergers, namely mergers involving three or more galaxies. We use the Illustris and IllustrisTNG cosmological hydrodynamical simulations to provide a theore…

Renormalization group corrections to $\Lambda$CDM model and observational consequences for $H_0$ tension
Nicolas R. Bertini, Marcos H. Novaes, Rodrigo von Marttens, Ilya L. Shapiro
https://arxiv.org/abs/2509.24026

Renormalization group corrections to $Λ$CDM model and observational consequences for $H_0$ tension
We explore the renormalization group-based extension of the $Λ$CDM model as a potential solution to the current cosmological tensions. In this approach, both the cosmological constant density and Newton's constant are allowed to vary with the energy scale, as a consequence of the remnant effects of massive quantum fields in the low-energy regime. The corresponding cosmological model is consistent with the principles of quantum field theory, based on the covariance of the vacuum effective actio…

Constranits of dynamical dark energy models from different observational datasets
Peiyuan Xu, Lu Chen, Guohao Li, Yang Han
https://arxiv.org/abs/2510.10439 https://

Constranits of dynamical dark energy models from different observational datasets
The measurements of baryon acoustic oscillation by the Dark Energy Spectroscopic Instrument Data Release 2 indicate that dark energy may be a dynamical quantity with a time-varying equation of state. This challenges the core assumptions of the $Λ$CDM model and has generated significant interest in dynamical dark energy models. Therefore, studying the parameterization of the equation of state for dynamical dark energy is crucial. Existing work has achieved fruitful results in the dark energy mo…

The Dependence of Halo Clustering on Subhalo Anisotropy and Planarity
Nathaniel P. Johnson, Andrew R. Zentner
https://arxiv.org/abs/2510.08293 https://arxi…

The Dependence of Halo Clustering on Subhalo Anisotropy and Planarity
We show that host cold dark matter (CDM) haloes cluster in a manner that depends upon the anisotropy/planarity of their subhaloes, indicating an environmental dependence to subhalo anisotropy/planarity. The spatial distribution of satellite galaxies about central galaxies and correspondingly, the spatial distribution of subhaloes about host haloes have been subjects of interest for two decades. Important questions include the degree to which satellites are distributed anisotropically about thei…

Updated constraints on interacting dark energy: A comprehensive analysis using multiple CMB probes, DESI DR2, and supernovae observations
Tian-Nuo Li, Guo-Hong Du, Yun-He Li, Yichao Li, Jia-Le Ling, Jing-Fei Zhang, Xin Zhang
https://arxiv.org/abs/2510.11363

Updated constraints on interacting dark energy: A comprehensive analysis using multiple CMB probes, DESI DR2, and supernovae observations
Recent DESI baryon acoustic oscillation (BAO) measurements, combined with Planck cosmic microwave background (CMB) data and DESY5 type Ia supernova (SN) data, indicate a significant deviation from $Λ$CDM, which seems to suggest that this deviation can be explained by an interaction between dark energy and dark matter. In this work, we perform a comprehensive analysis by utilizing the latest DESI DR2 BAO data in conjunction with CMB data from ACT, SPT, Planck, and WMAP, along with SN data from …

Beyond CPL: Evidence for dynamical dark energy in three-parameter models
Sonej Alam, Md. Wali Hossain
https://arxiv.org/abs/2510.03779 https://arxiv.org/pd…

Beyond CPL: Evidence for dynamical dark energy in three-parameter models
We introduce three-parameter extensions of the two-parameter minimal Akhtar-Hossain (mAH) parametrization, termed modified minimal AH (MmAH1,2), which provide greater flexibility in the dynamics of dark energy. These models are compared with $Λ$CDM, $w$CDM, mAH, CPL, and three-parameter CPL (CPL-$w_{\rm b}$) using a joint data set of the CMB compressed likelihood, DESI DR2, Pantheon$+$ supernovae, $H(z)$ measurements, and redshift-space distortions. While the common cosmological parameters rem…

Self-interacting dark matter in the center of a Local Group dwarf galaxy and its satellites
Thales A. Gutcke, Giulia Despali, Stephanie O'Neil, Mark Vogelsberger, Azadeh Fattahi, David B. Sanders
https://arxiv.org/abs/2510.05258

Self-interacting dark matter in the center of a Local Group dwarf galaxy and its satellites
We present a detailed comparison of a Local Group dwarf galaxy analogue evolved in two cosmological models: the standard $Λ$CDM and a self-interacting dark matter (SIDM) model with a velocity-dependent cross-section. Both simulations are run with the high-resolution, hydrodynamical LYRA galaxy formation model, allowing us to explore the global and substructure properties of the dwarf in a consistent context. While the overall halo growth, final mass, and subhalo mass functions remain largely u…

Theory space and stability analysis of General Relativistic cosmological solutions in modified gravity
Saikat Chakraborty, Piyabut Burikham
https://arxiv.org/abs/2509.15762 http…

Theory space and stability analysis of General Relativistic cosmological solutions in modified gravity
Some aspects of two General Relativistic cosmological solutions, an exact $Λ$CDM-like cosmological solution $j=1$ ($j$ is cosmographic jerk parameter), and a specifically designed toy cosmological solution $j=1+3\varepsilon(q-1/2)$ ($q$ is cosmographic deceleration parameter, $0<|\varepsilon|<1$) that is capable of accommodating a phantom crossing scenario as suggested by DESI DR2, are studied within the context of $f(R)$ gravity, by portraying them as a \emph{flow} in the 2-dimensio…

Extending CSST Emulator to post-DESI era
Zhao Chen, Yu Yu
https://arxiv.org/abs/2510.09503 https://arxiv.org/pdf/2510.09503

Extending CSST Emulator to post-DESI era
The recent DESI BAO measurements have revealed a potential deviation from a cosmological constant, suggesting a dynamic nature of dark energy. To rigorously test this result, complementary probes such as weak gravitational lensing are crucial, demanding highly accurate and efficient predictions of the nonlinear matter power spectrum within the $w_0w_a$CDM framework. However, most existing emulators fail to cover the full parameter posterior from DESI DR2+CMB constraints in the $w_0\mbox{-}w_a$ …

Constraints on the interacting holographic dark energy models: implications from background and perturbations data
N. Nazari Pooya
https://arxiv.org/abs/2510.08875 https://

Constraints on the interacting holographic dark energy models: implications from background and perturbations data
In this study, we employ a two-step method to analyze models of holographic dark energy (HDE) and interacting holographic dark energy (IHDE), incorporating three distinct dark energy (DE)-dark matter (DM) interaction terms. First, using the latest background dataset, we conduct a Markov chain Monte Carlo (MCMC) analysis to constrain the free parameters of the models. Then, we assess the models against each other using the key background parameters and compare them to the $Λ$CDM standard model.…

Constraints on dark matter models from the stellar cores observed in ultra-faint dwarf galaxies: Self-interacting dark matter
Jorge Sanchez Almeida (Instituto de Astrofisica de Canarias, La Laguna, Tenerife, E-38200, Spain, Departamento de Astrofisica, Universidad de La Laguna, Spain)
https://arxiv.org/abs/2510.05682

Constraints on dark matter models from the stellar cores observed in ultra-faint dwarf galaxies: Self-interacting dark matter
It has been proposed that the stellar cores observed in ultra-faint dwarf (UFD) galaxies reflect underlying dark matter (DM) cores that cannot be formed by stellar feedback acting on collisionless cold dark matter (CDM) halos. Assuming this claim is correct, we investigate the constraints that arise if such cores are produced by self-interacting dark matter (SIDM). We derive the range of SIDM cross-sections (sigma/m) required to reproduce the observed core sizes. These can result from halos in …

BAO miscalibration cannot rescue late-time solutions to the Hubble tension
Davide Pedrotti, Luis A. Escamilla, Valerio Marra, Leandros Perivolaropoulos, Sunny Vagnozzi
https://arxiv.org/abs/2510.01974 …

BAO miscalibration cannot rescue late-time solutions to the Hubble tension
Baryon Acoustic Oscillation (BAO) measurements play a key role in ruling out post-recombination solutions to the Hubble tension. However, because the data compression leading to these measurements assumes a fiducial $Λ$CDM cosmology, their reliability in testing late-time modifications to $Λ$CDM has at times been called into question. We play devil's advocate and posit that fiducial cosmology assumptions do indeed affect BAO measurements in such a way that low-redshift acoustic angular scales…

The Cosmic Rush Hour: Rapid Formation of Bright, Massive, Disky, Star-Forming Galaxies as Signatures of Early-Universe Physics
Xuejian Shen, Oliver Zier, Mark Vogelsberger, Michael Boylan-Kolchin, Lars Hernquist, Sandro Tacchella, Rohan P. Naidu
https://arxiv.org/abs/2509.19427

The Cosmic Rush Hour: Rapid Formation of Bright, Massive, Disky, Star-Forming Galaxies as Signatures of Early-Universe Physics
Early JWST observations have revealed a high-redshift universe more vibrant than predicted by canonical galaxy-formation models within $Λ$CDM, showing an excess of ultraviolet(UV)-bright, massive, and morphologically mature galaxies. Departures from $Λ$CDM prior to recombination can imprint signatures on non-linear structure formation at high redshift. In this paper, we investigate one such scenario - Early Dark Energy, originally proposed to resolve the Hubble tension - and its implications …

The Hubble Tension resolved by the DESI Baryon Acoustic Oscillations Measurements
X. D. Jia, J. P. Hu, D. H. Gao, S. X. Yi, F. Y. Wang
https://arxiv.org/abs/2509.17454 https://

The Hubble Tension resolved by the DESI Baryon Acoustic Oscillations Measurements
The $Λ$ cold dark matter ($Λ$CDM) cosmological model provides a good description of a wide range of astrophysical and cosmological observations. However, severe challenges to the phenomenological $Λ$CDM model have emerged recently, including the Hubble constant tension and the significant deviation from the $Λ$CDM model reported by the Dark Energy Spectroscopic Instrument (DESI) collaboration. Despite many explanations for the two challenges have been proposed, the origins of them are still…

On the shape of pancakes: catastrophe theory and Gaussian statistics in 2D
Abineet Parichha, Stephane Colombi, Shohei Saga, Atsushi Taruya
https://arxiv.org/abs/2509.25608 https…

On the shape of pancakes: catastrophe theory and Gaussian statistics in 2D
Cold dark matter (CDM) can be thought of as a 2D (or 3D) sheet of particles in 4D (or 6D) phase-space due to its negligible velocity dispersion. The large-scale structure, also called the cosmic web, is thus a result of the topology of the CDM manifold. Initial crossing of particle trajectories occurs at the critical points of this manifold, forming singularities that seed most of the collapsed structures. The cosmic web can thus be characterized using the points of singularities. In this conte…

Measurement of Dark Matter Substructure from the Kinematics of the GD-1 Stellar Stream
Jacob Nibauer, Ana Bonaca, Adrian M. Price-Whelan, David N. Spergel, Jenny E. Greene
https://arxiv.org/abs/2510.02247

Measurement of Dark Matter Substructure from the Kinematics of the GD-1 Stellar Stream
Stellar streams are sensitive tracers of low-mass dark matter subhalos and provide a means to test the Cold Dark Matter (CDM) paradigm on small scales. In this work, we connect the intrinsic velocity dispersion of the GD-1 stream to the number density and internal structure of dark matter subhalos in the mass range $10^5$-$10^9\ M_\odot$. We measure the radial velocity dispersion of GD-1 based on 160 identified member stars across four different spectroscopic catalogs. We use repeat observation…

Testing Lens Models of PLCK G165.7 67.0 Using Lensed SN H0pe
Aadya Agrawal, J. D. R. Pierel, Gautham Narayan, B. L. Frye, Jose M. Diego, Nikhil Garuda, Matthew Grayling, Anton M. Koekemoer, Kaisey S. Mandel, M. Pascale, David Vizgan, Rogier A. Windhorst
https://arxiv.org/abs/2510.07637

Testing Lens Models of PLCK G165.7+67.0 Using Lensed SN H0pe
Supernova H0pe is a multiply-imaged Type Ia supernova (SN Ia) and the second lensed SN to yield a measurement of the Hubble constant by the time-delay cosmography method, finding $H_0 = 75.4^{+8.1}_{-5.5} \text{km s}^{-1} \text{Mpc}^{-1}$. We investigate the seven lens modeling approaches used to derive $H_0$, assessing their agreement with $Λ\text{CDM}$ constraints from SN Ia surveys through a purely observational comparison. While photometrically derived magnifications yield distance moduli …

In-situ globular clusters in alternative dark matter Milky Way galaxies: a first approach to fuzzy and core-like dark matter theories
Pierre Boldrini, Paola Di Matteo
https://arxiv.org/abs/2510.02130

In-situ globular clusters in alternative dark matter Milky Way galaxies: a first approach to fuzzy and core-like dark matter theories
We present a first analysis of the dynamics of in-situ globular clusters (GCs) in Milky Way (MW)-like galaxies embedded in fuzzy dark matter (FDM) halos, combining cosmological assembly histories from the TNG50 simulation with dedicated orbital integrations and analytical models. GC populations are initialized with identical distributions in normalized $E$-$L_{z}$ in matched CDM and FDM halos. In a universe dominated by FDM, we identify three distinct regimes for the in-situ GC population depen…

Is CPL dark energy a mirage?
Mikel Artola, Ismael Ayuso, Ruth Lazkoz, Vincenzo Salzano
https://arxiv.org/abs/2510.04191 https://arxiv.org/pdf/2510.04191

Is CPL dark energy a mirage?
Recent observations from the Dark Energy Spectroscopic Instrument (DESI) raise doubts about the standard cosmological model, $Λ$CDM, suggesting a preference for an inherently dynamical dark energy component. The Chevallier-Polarski-Linder (CPL) parameterization -- a widely used two-parameter model for the dark energy equation of state -- displays marked early-time phantom behavior and a recent crossing of the phantom divide. These features suggest the convenience to check observationally the r…

Multiprobe constraints on early and late time dark energy
Alexander Reeves, Simone Ferraro, Andrina Nicola, Alexandre Refregier
https://arxiv.org/abs/2510.06114 https://

Multiprobe constraints on early and late time dark energy
We perform a multiprobe analysis combining cosmic microwave background (CMB) data from Planck and the Atacama Cosmology Telescope (ACT), ACT CMB lensing, and large-scale structure (LSS) measurements from the Dark Energy Spectroscopic Instrument (DESI), including DESI Legacy Imaging Survey (LS) galaxies and baryon acoustic oscillations (BAOs). We present the first $5\times2$pt analysis of ACT DR6 lensing, DESI LS, and Planck ISW. Within $Λ$CDM, this yields $S_8 = σ_8(Ω_m/0.3)^{0.5} = 0.819 \p…

Signatures of dark subhalos in dwarf spheroidal galaxies: I. Fluctuations in surface density
Eduardo Vitral, Jorge Pe\~narrubia, Matthew G. Walker
https://arxiv.org/abs/2509.26056

Signatures of dark subhalos in dwarf spheroidal galaxies: I. Fluctuations in surface density
Dark matter (DM) subhalos offer critical tests of cosmological models through their abundance and properties, yet most remain undetectable due to their lack of stars. We investigate whether their presence leaves measurable imprints on the projected stellar density fields of dwarf spheroidal galaxies (dSphs). Building on literature $N$-body experiments, we show that subhalo interactions induce subtle out-of-equilibrium fluctuations appearing as density corrugations. In a CDM framework, these flu…

Tests of Evolving Dark Energy with Geometric Probes of the Late Late-Time Universe
Kunhao Zhong, Bhuvnesh Jain
https://arxiv.org/abs/2509.26480 https://arx…

Tests of Evolving Dark Energy with Geometric Probes of the Late Late-Time Universe
Recent results from the Dark Energy Spectroscopic Instrument (DESI) have shown a strong statistical preference for a time-evolving dark energy model over $Λ$CDM when combining BAO, CMB, and supernova (SN) data. We investigate the robustness of this conclusion by isolating geometric information in weak lensing measurements from the DES Year 3 survey and combining it with different datasets. We introduce a hyperparameter, $Ω_{\rm m}^{\rm growth}$, to decouple the growth contribution from the le…

Inconsistencies of Tsallis Cosmology within Horizon Thermodynamics and Holographic Scenarios
Pedro M. Ibarbo P., J. Bayron Orjuela-Quintana, Jose L. Palacios-C\'ordoba, C\'esar A. Valenzuela-Toledo
https://arxiv.org/abs/2510.00234

Inconsistencies of Tsallis Cosmology within Horizon Thermodynamics and Holographic Scenarios
We investigate the cosmological implications of Tsallis entropy in two widely discussed settings: the Cai--Kim thermodynamic derivation of the Friedmann equations and the holographic dark energy (HDE) scenario with the Hubble scale as infrared cutoff. In both cases, the dynamics introduce a nonextensivity parameter $δ$, with standard $Λ$CDM recovered for $δ=1$. Previous studies have argued that only small deviations from extensivity are observationally allowed, typically constraining $|…

Cosmological constraints on non-phantom dynamical dark energy with DESI Data Release 2 Baryon Acoustic Oscillations: A 3$\sigma$ lensing anomaly
Shouvik Roy Choudhury, Teppei Okumura, Keiichi Umetsu
https://arxiv.org/abs/2509.26144

Cosmological constraints on non-phantom dynamical dark energy with DESI Data Release 2 Baryon Acoustic Oscillations: A 3$σ$+ lensing anomaly
We consider a 12-parameter cosmological model with non-phantom dynamical dark energy (NPDDE), where non-phantom implies that the equation of state (EoS) of dark energy (DE), $w(z)\geq-1$ for all redshifts $z$. Thus, the DE EoS covers the parameter space corresponding to the popular single scalar-field dark energy models, i.e., Quintessence. The cosmological model comprises 6 parameters of the $Λ$-Cold Dark Matter ($Λ$CDM) model, and additionally the dynamical DE EoS parameters ($w_0$, $w_a$),…

Constraining GREA, an alternative theory accounting for the present cosmic acceleration
R. Calderon, J. Garcia-Bellido, B. Vos-Gines, V. Gonzalez-Perez, A. Shafieloo, J. Aguilar, S. Ahlen, D. Bianchi, D. Brooks, T. Claybaugh, A. de la Macorra, J. E. Forero-Romero, E. Gazta\~naga, S. Gontcho A Gontcho, G. Gutierrez, K. Honscheid, C. Howlett, M. Ishak, R. Joyce, R. Kehoe, T. Kisner, A. Kremin, O. Lahav, A. Lambert, M. Landriau, M. Manera, R. Miquel, F. Prada, I. Perez-Rafols, E. Sanchez,…

Constraining GREA, an alternative theory accounting for the present cosmic acceleration
The origin of the Universe's late-time accelerated expansion remains unknown. The General Relativistic Entropic Acceleration (GREA) theory offers a compelling alternative to $Λ$CDM, attributing cosmic acceleration to entropy growth associated with cosmic and black hole horizons, without invoking a cosmological constant. We test GREA against the latest DESI DR2 Baryon Acoustic Oscillations (BAO), multiple Type Ia supernova compilations (Union3, Pantheon$\texttt{+}$, DES-SN5YR), and cosmic micro…

Evidence for increasing dark energy in DESI from the Local Distance Ladder
Maryam Aghaei Abchouyeh, Maurice H. P. M. van Putten
https://arxiv.org/abs/2509.23168 https://

Evidence for increasing dark energy in DESI from the Local Distance Ladder
The {\it Dark Energy Spectroscopic Instrument} (DESI) provides a comprehensive survey of {\it Baryon Acoustic Oscillation} (BAO) in the {\it Large Scale Structure} (LSS), {in stratified data covering a finite redshift range.} Extracting cosmological parameters in a joint analysis of LSS-CMB data is hereby inherently a nonlinear problem. In particular, this nonlinearity may concern the unknown equation of state of dark energy $w(a)$, defined in the general $w(a)$CDM framework. Nevertheless, a co…

Modified Cosmology or Modified Galaxy Astrophysics is Driving the z>6 JWST Results? CMB Experiments can discover the Origin in Near Future
Harsh Mehta, Suvodip Mukherjee
https://arxiv.org/abs/2509.21952

Modified Cosmology or Modified Galaxy Astrophysics is Driving the z>6 JWST Results? CMB Experiments can discover the Origin in Near Future
The massive and bright galaxies observed by the James Webb Space Telescope (JWST) at high redshifts ($z > 6$) have challenged our understanding of the Universe. This may require revisiting the physics of galaxy formation and evolution, or modifying the $Λ$CDM cosmological model to explain these observations, or both. We show that high-resolution CMB experiments such as the Simons Observatory (or CMB-S4) can measure smoking-gun signatures jointly in weak lensing and kinematic Sunyaev-Zeldovich …

CosmoGen: a cosmological model generator
D. Castel\~ao, I. Tereno
https://arxiv.org/abs/2509.15453 https://arxiv.org/pdf/2509.15453

CosmoGen: a cosmological model generator
The standard $Λ$CDM paradigm of the physical Universe suffers from well-known conceptual problems and is challenged by observational data. Alternative models exist in the literature, both phenomenological and physically motivated, many of them suffering from similar or new problems. We propose a method to mechanically generate alternative models in a procedure informed by data and tuned to mitigate specific problems. We implement a computational framework, dubbed CosmoGen, that integrates evol…

Late-Time Cosmological Constraints on Kaniadakis Holographic Dark Energy
Giuseppe Gaetano Luciano, Andronikos Paliathanasis
https://arxiv.org/abs/2509.17527 https://

Late-Time Cosmological Constraints on Kaniadakis Holographic Dark Energy
Kaniadakis Holographic Dark Energy is a one-parameter extension of the standard HDE framework, in which the horizon entropy is reformulated using Kaniadakis entropy. At the cosmological level, it has been shown to give rise to modified Friedmann equations, leading to a richer phenomenology compared to $Λ$CDM. In this work we test the Kanadiakis holography model against multiple late-time observational probes, including Type Ia supernovae from PantheonPlus and Union3, Cosmic Chronometer measure…