Tootfinder

This https://arxiv.org/abs/2403.02120 has been replaced.
link: https://scholar.google.com/scholar?q=a

Evaluating extensions to LCDM: an application of Bayesian model averaging
We employ Bayesian Model Averaging (BMA) as a powerful statistical framework to address key cosmological questions about the universe's fundamental properties. We explore extensions beyond the standard $Λ$CDM model, considering a varying curvature density parameter $Ω_{\rm k}$, a spectral index $\mathrm{n}_{\rm s}=1$ with running $d\mathrm{n}_{\rm s}/d\mathrm{k}$, a constant dark energy equation of state (EOS) $w_0-Λ$CDM and a time-dependent one $w_0w_a-Λ$CDM. We also test cosmological data…

This https://arxiv.org/abs/2006.11360 has been replaced.
link: https://scholar.google.com/scholar?q=a

CDM Based Virtual FMCW MIMO Radar Imaging at 79GHz
Multiple Input Multiple Output (MIMO) Frequency Modulated Continuous Wave (FMCW) radars operating at 79GHz are compact, light and cost effective devices with low peak-to-average power ratio that have applications in different areas such as automotive industry and Unmanned Arial Vehicle (UAV) based radar imaging. In order to keep the structure small and simple, these radars come with small number of transmitters and receivers. The number of elements can be virtually increased using techniques su…

This https://arxiv.org/abs/2312.12493 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Hubble tension as a window on the gravitation of the dark matter sector
A simple and minimal extension of the standard cosmological $Λ$CDM model in which dark matter experiences an additional long-range scalar interaction is demonstrated to alleviate the long lasting Hubble-tension while letting primordial nucleosynthesis predictions unaffected and passing by construction all current local tests of general relativity. The theoretical formulation of this $Λβ$CDM model and its comparison to astrophysical observations are presented to prove its ability to fit exist…

Tracing satellite planes in the Sculptor group: II. Discovery of five faint dwarf galaxies in the DESI Legacy Survey
David Martinez-Delgado, Michael Stein, Marcel S. Pawlowski, Dmitry Makarov, Lidia Makarova, Giuseppe Donatiello, Dustin Lang
https://arxiv.org/abs/2405.03769

Tracing satellite planes in the Sculptor group: II. Discovery of five faint dwarf galaxies in the DESI Legacy Survey
The problem of missing satellites still remains one of the well-known problems of the Lambda-CDM cosmological theory. Despite significant progress in cosmological modeling achieved in recent years, the search for new dwarf galaxies-satellites of nearby giant galaxies remains extremely important. In this series of papers we report the first results of an on-going systematic survey of faint dwarf spheroidal galaxies in the vicinity of the bright late-type spiral NGC 253 galaxy, the brightest memb…

Modified $f(Q)$ gravity models and their cosmological consequences
Gaurav N. Gadbail, P. K. Sahoo
https://arxiv.org/abs/2405.01594 https://

Modified $f(Q)$ gravity models and their cosmological consequences
In this work, we consider three different $f(Q)$ models, such as power-law, exponential, and logarithmic, to study which model better mimics $Λ$CDM evolution theoretically. Henceforth, we determine solutions to the $f(Q)$ gravity field equations in the isotropic and homogeneous universe. Since all the models contain two model parameters, we reduce the degrees of freedom using the first Friedman equation at the present time. Further, we check the behavior of cosmological parameters using the ob…

This https://arxiv.org/abs/2403.02120 has been replaced.
link: https://scholar.google.com/scholar?q=a

Evaluating extensions to LCDM: an application of Bayesian model averaging
We employ Bayesian Model Averaging (BMA) as a powerful statistical framework to address key cosmological questions about the universe's fundamental properties. We explore extensions beyond the standard $Λ$CDM model, considering a varying curvature density parameter $Ω_{\rm k}$, a spectral index $\mathrm{n}_{\rm s}=1$ with running $d\mathrm{n}_{\rm s}/d\mathrm{k}$, a constant dark energy equation of state (EOS) $w_0-Λ$CDM and a time-dependent one $w_0w_a-Λ$CDM. We also test cosmological data…

Tbh I really like the idea of superstar DJs performing errors to an unsuspecting crowd @… https://cdm.link/2024/04/grimes-coachella/

This https://arxiv.org/abs/2305.05337 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_grqc_…

Dynamical reconstruction of the $Λ$CDM model in scalar-tensor $f(R,T)$ gravity
In this work, we use the dynamical system approach to explore the cosmological background evolution of the scalar-tensor representation of $f(R,T)$ gravity, where $R$ is the Ricci scalar and $T$ is the trace of the stress-energy tensor. The motivation for this work resides in finding dynamical cosmological behaviors comparable with the $Λ$CDM model without the necessity of recurring to a dark energy component. We introduce a set of dynamical variables that allow for a direct comparison with th…

The true number density of massive galaxies in the early Universe revealed by JWST/MIRI
Tao Wang, Hanwen Sun, Luwenjia Zhou, Ke Xu, Cheng Cheng, Zhaozhou Li, Yangyao Chen, H. J. Mo, Avishai Dekel, Xianzhong Zheng, Zheng Cai, Tiacheng Yang, Y. -S. Dai, David Elbaz, J. -S. Huang
https://arxiv.org/abs/2403.02399 https://arxiv.org/pdf/2403.02399
arXiv:2403.02399v1 Announce Type: new
Abstract: One of the main challenges in galaxy formation that has emerged recently is the early assembly of massive galaxies. The observed number density and the maximum stellar mass ($M_{\star}$) of massive galaxies in the early Universe appear to be higher than model predictions, which may pose a serious problem to the LCDM cosmology. A major limitation in many previous studies is the large uncertainty in estimating $M_{\star}$ due to the lack of constraints in the rest-frame near-infrared part of the spectral energy distribution, which is critical to determining $M_{\star}$ accurately. Here we use data from a large JWST/MIRI survey in the PRIMER program to carry out a systematic analysis of massive galaxies at $z \sim 3-8$, leveraging photometric constraints at rest-frame $\gtrsim 1 \mu$m. We find a significant reduction in the number and mass densities of massive galaxies at $z > 5$ compared to earlier results that did not use the MIRI photometry. Within the standard $\Lambda$CDM cosmology, our results require a moderate increase in the baryon-to-star conversion efficiency ($\epsilon$) towards higher redshifts and higher $M_{\star}$. For the most massive galaxies at $z\sim 8$, the required $\epsilon$ is $\sim 0.3$, in comparison to $\epsilon \sim 0.14$ for typical low-redshift galaxies. Our findings are consistent with models assuming suppressed stellar feedback due to the high gas density and the associated short free-fall time expected for massive halos at high redshift.

This https://arxiv.org/abs/2312.12408 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Hubble tension as a window on the gravitation of the dark matter sector: Exploration of a family of models
A family of simple and minimal extensions of the standard cosmological $Λ$CDM model in which dark matter experiences an additional long-range scalar interaction is demonstrated to alleviate the long lasting Hubble-tension while letting primordial nucleosynthesis predictions unaffected and passing by construction all current local tests of general relativity. This article describes their theoretical formulation and their implications for dark matter. Then, it investigates their cosmological sig…

Space Music
#fiorellaterenzi #Astrodon #sonification

This https://arxiv.org/abs/2305.05337 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_grqc_…

Dynamical reconstruction of the $Λ$CDM model in scalar-tensor $f(R,T)$ gravity
In this work, we use the dynamical system approach to explore the cosmological background evolution of the scalar-tensor representation of $f(R,T)$ gravity, where $R$ is the Ricci scalar and $T$ is the trace of the stress-energy tensor. The motivation for this work resides in finding dynamical cosmological behaviors comparable with the $Λ$CDM model without the necessity of recurring to a dark energy component. We introduce a set of dynamical variables that allow for a direct comparison with th…

{\sc SimBIG}: Cosmological Constraints using Simulation-Based Inference of Galaxy Clustering with Marked Power Spectra
Elena Massara, ChangHoon Hahn, Michael Eickenberg, Shirley Ho, Jiamin Hou, Pablo Lemos, Chirag Modi, Azadeh Moradinezhad Dizgah, Liam Parker, Bruno R\'egaldo-Saint Blancard
https://arxiv.org/abs/2404.04228…

{\sc SimBIG}: Cosmological Constraints using Simulation-Based Inference of Galaxy Clustering with Marked Power Spectra
We present the first $Λ$CDM cosmological analysis performed on a galaxy survey using marked power spectra. The marked power spectrum is the two-point function of a marked field, where galaxies are weighted by a function that depends on their local density. The presence of the mark leads these statistics to contain higher-order information of the original galaxy field, making them a good candidate to exploit the non-Gaussian information of a galaxy catalog. In this work we make use of \simbig, …

This https://arxiv.org/abs/2309.08451 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Modified temperature redshift relation and UHECR propagation
We re-examine the interactions of ultra-high energy cosmic rays (UHECRs) with photons from the cosmic microwave background (CMB) under a changed, locally non-linear temperature redshift relation $T(z)$. This changed temperature redshift relation has recently been suggested by the postulate of subjecting thermalised and isotropic photon gases such as the CMB to an SU(2) rather than a U(1) gauge group. This modification of $Λ$CDM is called SU(2)$_{\rm CMB}$, and some cosmological parameters obta…

JWST PRIMER: A new multi-field determination of the evolving galaxy UV luminosity function at redshifts $\mathbf{z \simeq 9-15}$
C. T. Donnan, R. J. McLure, J. S. Dunlop, D. J. McLeod, D. Magee, K. Z. Arellano-C\'ordova, L. Barrufet, R. Begley, R. A. A. Bowler, A. C. Carnall, F. Cullen, R. S. Ellis, A. Fontana, G. D. Illingworth, N. A. Grogin, M. L. Hamadouche, A. M. Koekemoer, Feng-Yuan Liu, C. Mason, P. Santini, T. M. Stanton
https://arxiv.org/abs/2403.03171 https://arxiv.org/pdf/2403.03171
arXiv:2403.03171v1 Announce Type: new
Abstract: We present a new determination of the evolving galaxy UV luminosity function (LF) over the redshift range $8.5<15.5$ using a combination of several major Cycle-1 JWST imaging programmes - PRIMER, JADES and NGDEEP. This multi-field approach yields a total of $\simeq370$ sq. arcmin of JWST/NIRCam imaging, reaching (5-$\sigma$) depths of $\simeq30$ AB mag in the deepest regions. We select a sample of 2548 galaxies with a significant probability of lying at high redshift ($p(z>8.5)>0.05$) to undertake a statistical calculation of the evolving UV LF. Our new measurements span $\simeq4$ magnitudes in UV luminosity at $z=9-12.5$, placing new constraints on both the shape and evolution of the LF at early times. We fit our observational data-points with a double-power law (DPL) function and explore the evolution of the DPL parameters. Our UV LF measurements yield a new estimate of the early evolution of cosmic star-formation rate density ($\rho_{\rm{SFR}}$) which confirms the gradual, log-linear decline deduced from early JWST studies, at least out to $z \simeq 12$. Finally we show that the observed early evolution of the galaxy UV LF (and $\rho_{\rm{SFR}}$) can be reproduced in a ${\rm \Lambda}$CDM Universe, with no change in dust properties or star-formation efficiency required out to $z \simeq 12$. Instead, we show that a progressive trend towards younger stellar population ages can reproduce the observations, and we show that the typical ages required at $z \simeq$ 8, 9, 10, and 11 all converge on a time $\simeq 380-330$ Myr after the Big Bang, indicative of a rapid emergence of early galaxies at $z \simeq 12 - 13$. This is consistent with the first indications of a steeper drop-off in the galaxy population we find beyond $z \simeq 13$, possibly reflecting the rapid evolution of the halo mass function at earlier times.

MEET-U Project I: The key drivers of the preference for dynamic dark energy
Zhiqi Huang, Jianqi Liu, Jianfeng Mo, Yan Su, Junchao Wang, Yanhong Yao, Guangyao Yu, Zhengxin Zhu, Zhuoyang Li, Zhenjie Liu, Haitao Miao, Hui Tong
https://arxiv.org/abs/2405.03983

MEET-U Project I: The key drivers of the preference for dynamic dark energy
Joint analysis of the baryon acoustic oscillations (BAO) measurement by the Dark Energy Spectroscopic Instrument (DESI) first data release, Type Ia supernovae (SNe) of the Dark Energy Survey Year 5 (DES5YR) release and cosmic microwave background (CMB) data favors a quintom-like dynamic dark energy model over the standard Lambda cold dark matter ($Λ$CDM) model at $3.9σ$ level (Adame et al. 2024). We demonstrate that the preference for dynamic dark energy does not rely on the detailed modeling…

This https://arxiv.org/abs/2403.11916 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Sound Horizon Independent Constraints on Early Dark Energy: The Role of Supernova Data
We assess the consistency of cosmological models that alter the size of the sound horizon at last scattering to resolve the Hubble tension with data from ACT + Planck CMB lensing, Big Bang Nucleosynthesis, and supernova data from Pantheon or Pantheon+. We use early dark energy (EDE) as an example model but conclude that the results apply to other similar models. We constrain $Λ$CDM and EDE with these data finding that while they can constrain $Λ$CDM very tightly, EDE opens up the parameter sp…

This https://arxiv.org/abs/2403.11916 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Sound Horizon Independent Constraints on Early Dark Energy: The Role of Supernova Data
We assess the consistency of cosmological models that alter the size of the sound horizon at last scattering to resolve the Hubble tension with data from ACT + Planck CMB lensing, Big Bang Nucleosynthesis, and supernova data from Pantheon or Pantheon+. We use early dark energy (EDE) as an example model but conclude that the results apply to other similar models. We constrain $Λ$CDM and EDE with these data finding that while they can constrain $Λ$CDM very tightly, EDE opens up the parameter sp…

This https://arxiv.org/abs/2402.00060 has been replaced.
link: https://scholar.google.com/scholar?q=a

Treatment of Epistemic Uncertainty in Conjunction Analysis with Dempster-Shafer Theory
The paper presents an approach to the modelling of epistemic uncertainty in Conjunction Data Messages (CDM) and the classification of conjunction events according to the confidence in the probability of collision. The approach proposed in this paper is based on the Dempster-Shafer Theory (DSt) of evidence and starts from the assumption that the observed CDMs are drawn from a family of unknown distributions. The Dvoretzky-Kiefer-Wolfowitz (DKW) inequality is used to construct robust bounds on su…

This https://arxiv.org/abs/2307.10290 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_grqc_…

Dynamical dark energy from spacetime-symmetry breaking -- late-time behaviour and phantom crossing
We investigate the late-time cosmological dynamics in a simple case of explicit spacetime-symmetry breaking. By expanding in a small symmetry-breaking coefficient we are able to write the Friedmann equations as $Λ$CDM + dynamical dark energy, which we show contains logarithmic dependence of the scale factor. We find that the dark energy equation of state displays divergencies and phantom behaviour for certain values of the symmetry-breaking coefficient, where the NEC is also broken. We discuss…

Effects of anisotropy in an anisotropic extension of $w$CDM model
Vikrant Yadav, Santosh Kumar Yadav, Rajpal
https://arxiv.org/abs/2402.16885 https://

Effects of anisotropy in an anisotropic extension of $w$CDM model
In this paper, we derive observational constraints on an anisotropic $w$CDM model from observational data including Baryonic Acoustic Oscillations (BAOs), Cosmic Chronometer (CC), Big Bang Nucleosynthesis (BBN), Pantheon Plus (PP) compilation of Type Ia supernovae, and SH0ES Cepheid host distance anchors. We find that anisotropy is of the order $10^{-13}$, and its presence in the $w$CDM model reduces $H_0$ tension by $\sim 2σ$ and $\sim 1σ$ in the analyses with BAO+CC+BBN+PP and BAO+CC+BBN+PP…

CDM and SIDM Interpretations of the Strong Gravitational Lensing Object JWST-ER1
Demao Kong, Daneng Yang, Hai-Bo Yu
https://arxiv.org/abs/2402.15840 https:…

CDM and SIDM Interpretations of the Strong Gravitational Lensing Object JWST-ER1
van Dokkum et al. (arXiv:2309.07969) reported the discovery of JWST-ER1, a strong lensing object at redshift $z\approx2$, using data from the James Webb Space Telescope. The lens mass within the Einstein ring is $5.9$ times higher than the expected stellar mass from a Chabrier initial mass function, indicating a high dark matter density. In this work, we show that a cold dark matter halo, influenced by gas-driven adiabatic contraction, can account for the observed lens mass. We also derive cons…

Constraining neutrino-DM interactions with Milky Way dwarf spheroidals and supernova neutrinos
Sean Heston, Shunsaku Horiuchi, Satoshi Shirai
https://arxiv.org/abs/2402.08718

Constraining neutrino-DM interactions with Milky Way dwarf spheroidals and supernova neutrinos
We constrain the neutrino-dark matter cross section using properties of the dark matter density profiles of Milky Way dwarf spheroidal galaxies. The constraint arises from core-collapse supernova neutrinos scattering on dark matter as a form of energy injection, allowing the transformation of the dark matter density profile from a cusped profile to a flatter profile. We assume $\mathrmΛ$CDM, collisionless and non-self-interacting dark matter, and by requiring that the dark matter cores do not …

This https://arxiv.org/abs/2404.08633 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Does DESI 2024 Confirm $Λ$CDM?
We demonstrate that a $\sim 2 σ$ discrepancy with the Planck-$Λ$CDM cosmology in DESI Luminous Red Galaxy (LRG) data at $z_{\textrm{eff}} = 0.51$ translates into an unexpectedly large $Ω_m$ value, $Ω_m = 0.668^{+0.180}_{-0.169}$. We independently confirm that this anomaly drives the preference for $w_0 > -1$ in DESI data confronted to the $w_0 w_a$CDM model. We show that redshift bins of DESI constraints allow $Ω_m$ to wiggle at the $\sim 2 σ$ level with increasing effective redshift in t…

Optical properties of Euler-Heisenberg black hole in the Cold Dark Matter Halo
Lei You, Rui-bo Wang, Shi-Jie Ma, Jian-Bo Deng, Xian-Ru Hu
https://arxiv.org/abs/2403.12840

Optical properties of Euler-Heisenberg black hole in the Cold Dark Matter Halo
The optical properties of Euler-Heisenberg (EH) black hole (BH) surrounded by Cold Dark Matter (CDM) halo are investigated. By changing BH's parameters, we found that the radius of horizon r_{h} and radius of photon sphere r_{ph} will transparently increase as CDM halo parameters R and ρincrease. To show the influence of CDM halo on the BH's optical characteristics, we took two sets of R and ρwith prominent differences and plot the first four orders of images for thin accretion disk with diff…

This https://arxiv.org/abs/2205.05017 has been replaced.
link: https://scholar.google.com/scholar?q=a

$Λ$CDM is alive and well
The $Λ$CDM model faces several tensions with recent cosmological data and their increased accuracy. The mismatch between the values of the Hubble constant $H_0$ obtained from direct distance ladder measurements and from the cosmic microwave background (CMB) is the most statistically significant, but the amplitude of the matter fluctuations is also regarded as a serious concern, leading to the investigation of a plethora of models. We first show that the combination of several recent measuremen…

Modelling the star-formation activity and ionizing properties of high-redshift galaxies
Anirban Chakraborty, Tirthankar Roy Choudhury
https://arxiv.org/abs/2404.02879

Modelling the star-formation activity and ionizing properties of high-redshift galaxies
Early results from the JWST observations have reported a surprisingly high number of UV-bright galaxies at $z \geq 10$, which appears to challenge the theoretical predictions from standard galaxy formation models in the $Λ$CDM framework at these redshifts. To alleviate this tension, several cosmological and astrophysical interpretations have been advanced. However, all of these proposed scenarios carry noteworthy consequences for other large-scale processes in the early Universe, particularly …

This https://arxiv.org/abs/2309.04535 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Gravitational imaging through a triple source plane lens: revisiting the $Λ$CDM-defying dark subhalo in SDSSJ0946+1006
The $Λ$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 $Λ$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+1…

Using non-DESI data to confirm and strengthen the DESI 2024 spatially-flat $w_0w_a$CDM cosmological parameterization result
Chan-Gyung Park, Javier de Cruz Perez, Bharat Ratra
https://arxiv.org/abs/2405.00502

Using non-DESI data to confirm and strengthen the DESI 2024 spatially-flat $w_0w_a$CDM cosmological parameterization result
We use a combination of Planck cosmic microwave background (CMB) anisotropy data and non-CMB data that include Pantheon+ type Ia supernovae, Hubble parameter [$H(z)$], growth factor ($fσ_8$) measurements, and a collection of baryon acoustic oscillation (BAO) data, but not recent DESI 2024 BAO measurements, to confirm the DESI 2024 (DESI+CMB+PantheonPlus) data compilation support for dynamical dark energy with an evolving equation of state parameter $w(z) = w_0 + w_a z/(1+z)$. From our joint co…

This https://arxiv.org/abs/2402.15840 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

CDM and SIDM Interpretations of the Strong Gravitational Lensing Object JWST-ER1
van Dokkum et al. (arXiv:2309.07969) reported the discovery of JWST-ER1, a strong lensing object at redshift $z\approx2$, using data from the James Webb Space Telescope. The lens mass within the Einstein ring is $5.9$ times higher than the expected stellar mass from a Chabrier initial mass function, indicating a high dark matter density. In this work, we show that a cold dark matter halo, influenced by gas-driven adiabatic contraction, can account for the observed lens mass. We interpret the me…

Early dark energy and scalarization in a scalar-tensor model
H. Mohseni Sadjadi
https://arxiv.org/abs/2404.19695 https://arxiv.org/pdf/2404.19695
arXiv:2404.19695v1 Announce Type: new
Abstract: We present a model in which the Gauss-Bonnet invariant holds the quintessence at a fixed point, respecting an initial $Z_2$ symmetry in the radiation-dominated era. This results in an early dark energy, which becomes significant around the matter-radiation equality era. However, due to $Z_2$ symmetry breaking, scalarization occurs, leading to a rapid reduction in the early dark energy density. The model then quickly behaves like the $\Lambda$CDM model. This scenario alleviates the Hubble tension and aligns with the assumption that the gravitational wave speed is infinitesimally close to the speed of light.

Updated observational constraints on spatially-flat and non-flat $\Lambda$CDM and XCDM cosmological models
Javier de Cruz Perez, Chan-Gyung Park, Bharat Ratra
https://arxiv.org/abs/2404.19194

Updated observational constraints on spatially-flat and non-flat $Λ$CDM and XCDM cosmological models
We study 6 LCDM models, with 4 allowing for non-flat geometry and 3 allowing for a non-unity lensing consistency parameter $A_L$. We also study 6 XCDM models with a dynamical dark energy density X-fluid with equation of state $w$. For the non-flat models we use two different primordial power spectra, Planck $P(q)$ and new $P(q)$. These models are tested against: Planck 2018 CMB power spectra (P18) and lensing potential power spectrum (lensing), and an updated compilation of BAO, SNIa, $H(z)$, a…

This https://arxiv.org/abs/2402.04767 has been replaced.
link: https://scholar.google.com/scholar?q=a

$Λ$CDM Tensions: Localising Missing Physics through Consistency Checks
$Λ$CDM tensions are by definition model dependent; one sees anomalies through the prism of $Λ$CDM. Thus, progress towards tension resolution necessitates checking the consistency of the $Λ$CDM model to localise missing physics either in redshift or scale. Since the Universe is dynamical and redshift is a proxy for time, it is imperative to first perform consistency checks involving redshift, then consistency checks involving scale, as the next steps to settle the ``systematics versus new phy…

This https://arxiv.org/abs/2310.02914 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_grqc_…

f(R) Gravity in an Ellipsoidal Universe
We propose a new model of cosmology based on an anisotropic background and a specific $f(R)$ theory of gravity. It is shown that field equations of $f(R)$ gravity in a Bianchi type I background give rise to a modified Friedmann equation. This model contains two important parameters: $γ$ and $δ$. We, thus, simply call our model $γδ$CDM. It is distinguished in two important aspects from the $Λ$CDM model: firstly, the contribution of different energy densities to the Hubble parameter are weig…

This https://arxiv.org/abs/2402.04767 has been replaced.
link: https://scholar.google.com/scholar?q=a

$Λ$CDM Tensions: Localising Missing Physics through Consistency Checks
$Λ$CDM tensions are by definition model dependent; one sees anomalies through the prism of $Λ$CDM. Thus, progress towards tension resolution necessitates checking the consistency of the $Λ$CDM model to localise missing physics either in redshift or scale. Since the Universe is dynamical and redshift is a proxy for time, it is imperative to first perform consistency checks involving redshift, then consistency checks involving scale, as the next steps to settle the ``systematics versus new phy…

This https://arxiv.org/abs/2310.03063 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

$Λ$CDM not dead yet: massive high-z Balmer break galaxies are less common than previously reported
Early JWST observations that targeted so-called double-break sources (attributed to Lyman and Balmer breaks at $z>7$), reported a previously unknown population of very massive, evolved high-redshift galaxies. This surprising discovery led to a flurry of attempts to explain these objects' unexpected existence including invoking alternatives to the standard $Λ$CDM cosmological paradigm. To test these early results, we adopted the same double-break candidate galaxy selection criteria to search fo…

syren-halofit: A fast, interpretable, high-precision formula for the $\Lambda$CDM nonlinear matter power spectrum
Deaglan J. Bartlett, Benjamin D. Wandelt, Matteo Zennaro, Pedro G. Ferreira, Harry Desmond
https://arxiv.org/abs/2402.17492

syren-halofit: A fast, interpretable, high-precision formula for the $Λ$CDM nonlinear matter power spectrum
Rapid and accurate evaluation of the nonlinear matter power spectrum, $P(k)$, as a function of cosmological parameters and redshift is of fundamental importance in cosmology. Analytic approximations provide an interpretable solution, yet current approximations are neither fast nor accurate relative to black-box numerical emulators. We use symbolic regression to obtain simple analytic approximations to the nonlinear scale, $k_σ$, the effective spectral index, $n_{\rm eff}$, and the curvature, $…

Antisymmetric galaxy cross-correlations in and beyond $\Lambda$CDM
Eleonora VanzanUniversity of Padova, INFN Padova, Alvise RaccanelliUniversity of Padova, INFN Padova, INAF OAPD, Nicola BartoloUniversity of Padova, INFN Padova, INAF OAPD
https://arxiv.org/abs/2402.14782

Antisymmetric galaxy cross-correlations in and beyond $Λ$CDM
Many different techniques to analyze galaxy clustering data and obtain cosmological constraints have been proposed, tested and used. Given the large amount of data that will be available soon, it is worth investigating new observables and ways to extract information from such datasets. In this paper, we focus on antisymmetric correlations, that arise in the cross-correlation of different galaxy populations when the small-scale power spectrum is modulated by a long-wavelength field. In $Λ$CDM t…

Gravitational Lensing and Clues of $r_{d}$ and $H_{0}$ Tension: Viscous Modified Chaplygin Gas and Variable Modified Chaplygin Gas in Loop Quantum Cosmology
Rownak Kundu, Ujjal Debnath, Himanshu Chaudhary, G. Mustafa
https://arxiv.org/abs/2402.07515

Gravitational Lensing and Clues of $r_{d}$ and $H_{0}$ Tension: Viscous Modified Chaplygin Gas and Variable Modified Chaplygin Gas in Loop Quantum Cosmology
This paper explores the accelerated cosmic expansion in the late Universe through the investigation of two dark energy models: viscous modified Chaplygin gas (VsMCG) and variable modified Chaplygin gas (VMCG), alongside the $Λ$CDM model. Our goal is to constrain fundamental cosmic parameters in these dark energy models with the $Λ$CDM model using 30 of the latest $H(z)$ measurements from the cosmic chronometers method (CC), including Type Ia Supernovae, Gamma-Ray Bursts (GRB), Quasars, and 24…

Antisymmetric galaxy cross-correlations in and beyond $\Lambda$CDM
Eleonora VanzanUniversity of Padova, INFN Padova, Alvise RaccanelliUniversity of Padova, INFN Padova, INAF OAPD, Nicola BartoloUniversity of Padova, INFN Padova, INAF OAPD
https://arxiv.org/abs/2402.14782

Antisymmetric galaxy cross-correlations in and beyond $Λ$CDM
Many different techniques to analyze galaxy clustering data and obtain cosmological constraints have been proposed, tested and used. Given the large amount of data that will be available soon, it is worth investigating new observables and ways to extract information from such datasets. In this paper, we focus on antisymmetric correlations, that arise in the cross-correlation of different galaxy populations when the small-scale power spectrum is modulated by a long-wavelength field. In $Λ$CDM t…

An attractive model: simulating fuzzy dark matter with attractive self-interactions
Connor A. Painter, Michael Boylan-Kolchin, Philip Mocz, Mark Vogelsberger
https://arxiv.org/abs/2402.16945

An attractive model: simulating fuzzy dark matter with attractive self-interactions
Fuzzy Dark Matter (FDM) comprised of ultralight ($m \sim 10^{-22}~\rm{eV}$) boson particles has received significant attention as a viable alternative to Cold Dark Matter (CDM), as it approximates CDM on large scales ($\gtrsim 1$ Mpc) while potentially resolving some of its small-scale problems via kiloparsec-scale quantum interference. However, the most basic FDM model, with one free parameter (the boson mass), is subject to a tension: small boson masses yield the desired cores of dwarf galaxi…

This https://arxiv.org/abs/2308.00342 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_grqc_…

Reconstruction of aether scalar tensor theory for various cosmological scenarios
In this paper, we present several explicit reconstructions for {the aether scalar tensor (AeST) theory} derived from the background of Friedmann-Lema$\hat{\textı}$tre-Robertson-Walker cosmological evolution. It is shown that the Einstein-Hilbert Lagrangian with a positive cosmological constant is the only Lagrangian capable of accurately replicating the exact expansion history of the $Λ$ cold dark matter ($Λ$CDM) universe filled solely with dust-like matter. However, the $Λ$CDM-era can be p…

This https://arxiv.org/abs/2309.15711 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Beyond $Λ$CDM with $f(z)$CDM: criticalities and solutions of Padé Cosmography
Recently, cosmography emerged as a valuable tool to effectively describe the vast amount of astrophysical observations without relying on a specific cosmological model. Its model-independent nature ensures a faithful representation of data, free from theoretical biases. Indeed, the commonly assumed fiducial model, the $Λ$CDM, shows some shortcomings and tensions between data at late and early times that need to be further investigated. In this paper, we explore an extension of the standard cos…

This https://arxiv.org/abs/2003.10420 has been replaced.
link: https://scholar.google.com/scholar?q=a

The impact of peculiar velocities on supernova cosmology
The existence of 'peculiar' velocities due to the formation of cosmic structure marks a point of discord between the real Universe and the usually assumed Friedmann-Lemaítre-Robertson-Walker metric which accomodates only the smooth Hubble expansion on large scales. In the standard $Λ$CDM model framework, Type Ia supernovae data are routinely "corrected" for the peculiar velocities of both the observer and the supernova host galaxies relative to the cosmic rest frame, in order to infer evidenc…

Satellite group infall into the Milky Way: exploring the Crater-Leo case with new HST proper motions
Mariana P. J\'ulio, Marcel S. Pawlowski, Sangmo Tony Sohn, Salvatore Taibi, Roeland P. van der Marel, Stacy S. McGaugh
https://arxiv.org/abs/2404.16110

Satellite group infall into the Milky Way: exploring the Crater-Leo case with new HST proper motions
Context. Within $Λ$ Cold Dark Matter ($Λ$CDM) simulations, Milky Way-like galaxies accrete some of their satellite galaxies in groups of 3-5 members rather than individually. It was also suggested that this might be the reason behind the origin of satellite planes. Objects accreted in groups are expected to share similar specific total energy and angular momentum, and also identical orbital planes and directions. Aims. Looking at observations of Milky Way satellites, the dwarf galaxies Leo II…

Testing the $\mathbf{\Lambda}$CDM Cosmological Model with Forthcoming Measurements of the Cosmic Microwave Background with SPT-3G
K. Prabhu, S. Raghunathan, M. Millea, G. Lynch, P. A. R. Ade, E. Anderes, A. J. Anderson, B. Ansarinejad, M. Archipley, L. Balkenhol, K. Benabed, A. N. Bender, B. A. Benson, F. Bianchini, L. E. Bleem, F. R. Bouchet, L. Bryant, E. Camphuis, J. E. Carlstrom, T. W. Cecil, C. L. Chang, P. Chaubal, P. M. Chichura, T. -L. Chou, A. Coerver, T. M. Crawford, A. Cukie…

Testing the $\mathbfΛ$CDM Cosmological Model with Forthcoming Measurements of the Cosmic Microwave Background with SPT-3G
We forecast constraints on cosmological parameters enabled by three surveys conducted with SPT-3G, the third-generation camera on the South Pole Telescope. The surveys cover separate regions of 1500, 2650, and 6000 ${\rm deg}^{2}$ to different depths, in total observing 25% of the sky. These regions will be measured to white noise levels of roughly 2.5, 9, and 12 $μ{\rm K-arcmin}$, respectively, in CMB temperature units at 150 GHz by the end of 2024. The survey also includes measurements at 95…

Testing Yukawa cosmology at the Milky Way and M31 galactic scales
Rocco D'Agostino, Kimet Jusufi, Salvatore Capozziello
https://arxiv.org/abs/2404.01846

Testing Yukawa cosmology at the Milky Way and M31 galactic scales
We address the galaxy rotation curves through the Yukawa gravitational potential emerging as a correction of the Newtonian potential in extended theories of gravity. On the one hand, we consider the contribution of the galactic bulge, galactic disk, and the dark matter halo of the Navarro-Frenk-White profile, in the framework of the standard $Λ$CDM model. On the other hand, we use modified Yukawa gravity to show that the rotational velocity of galaxies can be addressed successfully without the…

Does DESI 2024 Confirm $\Lambda$CDM?
Eoin \'O Colg\'ain, Maria Giovanna Dainotti, Salvatore Capozziello, Saeed Pourojaghi, M. M. Sheikh-Jabbari, Dejan Stojkovic
https://arxiv.org/abs/2404.08633

Does DESI 2024 Confirm $Λ$CDM?
We demonstrate that a $\sim 2 σ$ discrepancy with the Planck-$Λ$CDM cosmology in DESI Luminous Red Galaxy (LRG) data at $z_{\textrm{eff}} = 0.51$ translates into an unexpectedly large $Ω_m$ value, $Ω_m = 0.668^{+0.180}_{-0.169}$. We independently confirm that this anomaly drives the preference for $w_0 > -1$ in DESI data confronted to the $w_0 w_a$CDM model. We show that redshift bins of DESI constraints allow $Ω_m$ to wiggle at the $\sim 2 σ$ level with increasing effective redshift in t…

Does DESI 2024 Confirm $\Lambda$CDM?
Eoin \'O Colg\'ain, Maria Giovanna Dainotti, Salvatore Capozziello, Saeed Pourojaghi, M. M. Sheikh-Jabbari, Dejan Stojkovic
https://arxiv.org/abs/2404.08633

Does DESI 2024 Confirm $Λ$CDM?
We demonstrate that a $\sim 2 σ$ discrepancy with the Planck-$Λ$CDM cosmology in DESI Luminous Red Galaxy (LRG) data at $z_{\textrm{eff}} = 0.51$ translates into an unexpectedly large $Ω_m$ value, $Ω_m = 0.668^{+0.180}_{-0.169}$. We independently confirm that this anomaly drives the preference for $w_0 > -1$ in DESI data confronted to the $w_0 w_a$CDM model. We show that redshift bins of DESI constraints allow $Ω_m$ to wiggle at the $\sim 2 σ$ level with increasing effective redshift in t…

The Influence of Baryons on Low-mass Haloes
Haonan Zheng, Sownak Bose, Carlos S. Frenk, Liang Gao, Adrian Jenkins, Shihong Liao, Volker Springel, Jie Wang, Simon D. M. White
https://arxiv.org/abs/2403.17044

The Influence of Baryons on Low-mass Haloes
The Voids-within-Voids-within-Voids (VVV) project used dark-matter-only simulations to study the abundance and structure of dark matter haloes over the full mass range populated in the standard $Λ\mathrm{CDM}$ cosmology. Here we explore how baryonic effects modify these results for $z=0$ halo masses in the range $10^4$ to $10^7~\mathrm{M_\odot}$, below the threshold for galaxy formation. Our main study focuses on three simulations from identical initial conditions at $z=127$, one following dar…

This https://arxiv.org/abs/2212.13146 has been replaced.
link: https://scholar.google.com/scholar?q=a

Dark energy and matter interacting scenario can relieve $H_0$ and $S_8$ tensions
We consider a new cosmological model (named $\tildeΛ$CDM) in which the vacuum energy interacts with matter and radiation, and test this model using the current cosmological observations. Using the CMB+BAO+SN (CBS) data set to constrain the model, we find that the $H_0$ and $S_8$ tensions are relieved to $2.87σ$ and $2.77σ$, respectively. However, in this case, the $\tildeΛ$CDM model is not favored by the data, compared with $Λ$CDM. We find that when the $H_0$ and $S_8$ data are added into …

This https://arxiv.org/abs/2310.16911 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Observational Constraints on Dynamical Dark Energy Models
$ϕ$CDM models provide an alternative to the standard $Λ$CDM paradigm, while being physically better motivated. These models lead to a time-dependent speed of sound for dark energy that is difficult to replicate by $w$CDM parametrizations. We review the most up-to-date status of observational evidence for the $ϕ$CDM models in this paper. We start with an overview of the motivation behind these classes of models, the basic mathematical formalism, and the different classes of models. We then pr…

A critical discussion on the $H_0$ tension
Salvatore Capozziello, Giuseppe Sarracino, Giulia De Somma
https://arxiv.org/abs/2403.12796 https://

A critical discussion on the $H_0$ tension
A critical discussion on the $H_0$ Hubble constant tension is presented by considering both early and late-type observations. From recent precise measurements, discrepancies emerge when comparing results for some cosmological quantities obtained at different redshifts. We highlight the most relevant measurements of $H_0$ and propose potential ideas to solve its tension. These solutions concern the exploration of new physics beyond the $Λ$CDM model or the evaluation of $H_0$ by other methods. I…

This https://arxiv.org/abs/2310.16911 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Observational Constraints on Dynamical Dark Energy Models
$ϕ$CDM models provide an alternative to the standard $Λ$CDM paradigm, while being physically better motivated. These models lead to a time-dependent speed of sound for dark energy that is difficult to replicate by $w$CDM parametrizations. We review the most up-to-date status of observational evidence for the $ϕ$CDM models in this paper. We start with an overview of the motivation behind these classes of models, the basic mathematical formalism, and the different classes of models. We then pr…

Exploring the nature of dark matter with the extreme galaxy AGC 114905
Pavel E. Mancera Pi\~na, Giulia Golini, Ignacio Trujillo, Mireia Montes
https://arxiv.org/abs/2404.06537

Exploring the nature of dark matter with the extreme galaxy AGC 114905
AGC 114905 is a dwarf gas-rich ultra-diffuse galaxy seemingly in tension with the cold dark matter (CDM) model. Specifically, the galaxy appears to have an extremely low-density halo and a high baryon fraction, while CDM predicts dwarfs to have very dense and dominant dark haloes. The alleged tension relies on the galaxy's rotation curve decomposition, which depends heavily on its inclination. This inclination, estimated from the gas morphology, remains somewhat uncertain. We present unmatched …

How robust are the parameter constraints extending the $\Lambda$CDM model?
Stefano Gariazzo, William Giar\`e, Olga Mena, Eleonora Di Valentino
https://arxiv.org/abs/2404.11182

How robust are the parameter constraints extending the $Λ$CDM model?
We present model-marginalized limits on the six standard $Λ$CDM cosmological parameters ($Ω_{\rm c} h^2$, $Ω_{\rm b} h^2$, $θ_{\rm MC}$, $τ_{\rm reio}$, $n_s$ and $A_s$), as well as on selected derived quantities ($H_0$, $Ω_{\rm m}$, $σ_8$, $S_8$ and $r_{\rm drag}$), obtained by considering three independent Cosmic Microwave Background (CMB) experiments: the Planck satellite, the Atacama Cosmology Telescope, and South Pole Telescope. We also consider low redshift observations in the form…

Stochastic gravitational wave background generated by domain wall networks
D. Gr\"uber, L. Sousa, P. P. Avelino
https://arxiv.org/abs/2403.09816 https…

Stochastic gravitational wave background generated by domain wall networks
In this work we study the power spectrum of the Stochastic Gravitational Wave Background produced by standard and biased domain wall networks, using the Velocity-dependent One-Scale model to compute the cosmological evolution of their characteristic scale and root-mean-squared velocity. We consider a standard radiation + $Λ\rm CDM$ background and assume that a constant fraction of the energy of collapsing domain walls is emitted in the form of gravitational waves. We show that, in an expanding…

This https://arxiv.org/abs/2206.11447 has been replaced.
link: https://scholar.google.com/scholar?q=a

Putting Flat $Λ$CDM In The (Redshift) Bin
Flat $Λ$CDM cosmology is specified by two constant fitting parameters at the background level in the late Universe, the Hubble constant $H_0$ and matter density (today) $Ω_m$. Mathematically, $H_0$ and $Ω_m$ are either integration constants arising from solving ordinary differential equations or are directly related to integration constants. Seen in this context, if fits of the $Λ$CDM model to cosmological probes at different redshifts lead to different $(H_0, Ω_m)$ parameters, this is a m…

Stochastic gravitational wave background generated by domain wall networks
D. Gr\"uber, L. Sousa, P. P. Avelino
https://arxiv.org/abs/2403.09816 https…

Stochastic gravitational wave background generated by domain wall networks
In this work we study the power spectrum of the Stochastic Gravitational Wave Background produced by standard and biased domain wall networks, using the Velocity-dependent One-Scale model to compute the cosmological evolution of their characteristic scale and root-mean-squared velocity. We consider a standard radiation + $Λ\rm CDM$ background and assume that a constant fraction of the energy of collapsing domain walls is emitted in the form of gravitational waves. We show that, in an expanding…

This https://arxiv.org/abs/2402.05908 has been replaced.
link: https://scholar.google.com/scholar?q=a

Transition dynamics in the $Λ_{\rm s}$CDM model: Implications for bound cosmic structures
We explore the predictions of $Λ_{\rm s}$CDM, a novel framework suggesting a rapid anti-de Sitter (AdS) to de Sitter (dS) vacua transition in the late Universe, on bound cosmic structures. In its simplest version, the cosmological constant, $Λ_{\rm s}$, abruptly switches sign from negative to positive, attaining its present-day value at a redshift of ${z_\dagger\sim 2}$. The $Λ_{\rm s}$CDM model emerges as a promising solution to major cosmological tensions, particularly the $H_0$ and $S_8$ …

The Self-Consistency of DESI Analysis and Comment on "Does DESI 2024 Confirm $\Lambda$CDM?"
Deng Wang (IFIC, Spain)
https://arxiv.org/abs/2404.13833

The Self-Consistency of DESI Analysis and Comment on "Does DESI 2024 Confirm $Λ$CDM?"
We demonstrate that the constraints on the evolution of dark energy implemented by the DESI collaboration may be insufficient or incomplete using their own BAO data. Using large enough prior ranges for the present-day equation of state of dark energy $ω_0$ and amplitude of dark energy evolution $ω_a$, we obtain the complete $1\,σ$ and $2\,σ$ constraints $ω_0=1.04^{+0.91+2.00}_{-1.00-1.90}$ and $ω_a=-7.4^{+3.8+6.8}_{-3.2-7.3}$ indicating a beyond $2\,σ$ preference of quintessence-like dar…

Bayesian distances for quantifying tensions in cosmological inference and the surprise statistic
Benedikt Schosser, Pedro Riba Mello, Miguel Quartin, Bjoern Malte Schaefer
https://arxiv.org/abs/2402.19100

Bayesian distances for quantifying tensions in cosmological inference and the surprise statistic
Tensions between cosmological parameters derived through different channels can be a genuine signature of new physics that $Λ$CDM as the standard model is not able to reproduce, in particular in the missing consistency between parameter estimates from measurements the early and late Universe. Or, they could be caused by yet to be understood systematics in the measurements as a more mundane explanation. Commonly, cosmological tensions are stated in terms of mismatches of the posterior parameter…

$\Lambda_{\rm s}$CDM cosmology from a type-II minimally modified gravity
Ozgur Akarsu, Antonio De Felice, Eleonora Di Valentino, Suresh Kumar, Rafael C. Nunes, Emre Ozulker, J. Alberto Vazquez, Anita Yadav
https://arxiv.org/abs/2402.07716

$Λ_{\rm s}$CDM cosmology from a type-II minimally modified gravity
We have successfully integrated $Λ_{\rm s}$CDM, a promising model for alleviating cosmological tensions, into a theoretical framework by endowing it with a specific Lagrangian from the VCDM model, a type-II minimally modified gravity. In this theory, we demonstrate that an auxiliary scalar field with a linear potential induces an effective cosmological constant, enabling the realization of an abrupt mirror AdS-dS transition in the late universe through a piecewise linear potential. To eliminat…

This https://arxiv.org/abs/2309.03286 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

On dataset tensions and signatures of new cosmological physics
Can new cosmic physics be uncovered through tensions amongst datasets? Tensions in parameter determinations amongst different types of cosmological observation, especially the `Hubble tension' between probes of the expansion rate, have been invoked as possible indicators of new physics, requiring extension of the $Λ$CDM paradigm to resolve. Within a fully Bayesian framework, we show that the standard tension metric gives only part of the updating of model probabilities, supplying a data co-dep…

The galaxy-galaxy strong lensing cross section and the internal distribution of matter in {\Lambda}CDM substructure
Yarone M. Tokayer, Isaque Dutra, Priyamvada Natarajan, Guillaume Mahler, Mathilde Jauzac, Massimo Meneghetti
https://arxiv.org/abs/2404.16951

The galaxy-galaxy strong lensing cross section and the internal distribution of matter in ΛCDM substructure
Strong gravitational lensing offers a powerful probe of the detailed distribution of matter in lenses, while magnifying and bringing faint background sources into view. Observed strong lensing by massive galaxy clusters, which are often in complex dynamical states, has also been used to map their dark matter substructures on smaller scales. Deep high resolution imaging has revealed the presence of strong lensing events associated with these substructures, namely galaxy-scale sub-halos. However,…

The galaxy-galaxy strong lensing cross section and the internal distribution of matter in {\Lambda}CDM substructure
Yarone M. Tokayer, Isaque Dutra, Priyamvada Natarajan, Guillaume Mahler, Mathilde Jauzac, Massimo Meneghetti
https://arxiv.org/abs/2404.16951

The galaxy-galaxy strong lensing cross section and the internal distribution of matter in ΛCDM substructure
Strong gravitational lensing offers a powerful probe of the detailed distribution of matter in lenses, while magnifying and bringing faint background sources into view. Observed strong lensing by massive galaxy clusters, which are often in complex dynamical states, has also been used to map their dark matter substructures on smaller scales. Deep high resolution imaging has revealed the presence of strong lensing events associated with these substructures, namely galaxy-scale sub-halos. However,…

Primordial Magnetic Fields in Light of Dark Ages Global 21-cm Signal
Vivekanand Mohapatra, Pravin Kumar Natwariya, Alekha C. Nayak
https://arxiv.org/abs/2402.18565

Primordial Magnetic Fields in Light of Dark Ages Global 21-cm Signal
We study the constraints on the primordial magnetic fields in light of Dark Ages global 21-cm signal. An early absorption signal in the redshift of $200 \leq z \leq 30$ is predicted in the $Λ\rm CDM$ model of cosmology. During the Dark Ages, there were no stars, therefore, measuring the global 21-cm signal can provide pristine cosmological information. However, measuring the Dark Ages global 21-cm signal from ground-based telescopes is challenging. To overcome this difficulty, recently lunar a…

This https://arxiv.org/abs/2307.13455 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

The skewness of the distance-redshift relation in $Λ$CDM
Starting from a recently proposed framework for the evaluation of the cosmological averages, we evaluate the higher-order moments for the distribution of a given observable. Then, we explicitly discuss the case of the Hubble-Lemaître diagram and evaluate its skewness at the leading order in the cosmological perturbative expansion of the gravitational potential. In particular, we focus on perturbations of the luminosity distance due to gravitational lensing. Finally, we discuss our findings in …

This https://arxiv.org/abs/2401.13187 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Effects of type Ia supernovae absolute magnitude priors on the Hubble constant value
We systematically explore the influence of the prior of the peak absolute magnitude ($M$) of type Ia supernovae (SNe Ia) on the measurement of the Hubble constant ($H_0$) from SNe Ia observations. We consider five different data-motivated $M$ priors, representing varying levels of dispersion, and assume the spatially-flat $Λ$CDM cosmological model. Different $M$ priors lead to relative changes in the mean values of $H_0$ from 2% to 7%. Loose priors on $M$ yield $H_0$ estimates consistent with …

This https://arxiv.org/abs/2404.05722 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Quintessential interpretation of the evolving dark energy in light of DESI
The recent result of Dark Energy Spectroscopic Instrument (DESI) in combination with other cosmological data shows evidence of the evolving dark energy parameterized by $w_0w_a$CDM model. We interpret this result in terms of a quintessential scalar field and demonstrate that it can explain the DESI result even though it becomes eventually phantom in the past. Relaxing the assumption on the functional form of the equation-of-state parameter $w=w(a)$, we also discuss a more realistic quintessenti…

This https://arxiv.org/abs/2301.12725 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Negative Dark Energy Density from High Redshift Pantheon+ Supernovae
Within the Friedmann-Lemaître-Robertson-Walker (FLRW) framework, the Hubble constant $H_0$ is an integration constant. Thus, consistency of the model demands observational constancy of $H_0$. We demonstrate redshift evolution of best fit $Λ$CDM parameters $(H_0, Ω_{m})$ in Pantheon+ supernove (SNe). Redshift evolution of best fit cosmological parameters is a prerequisite to finding a statistically significant evolution as well as identifying alternative models that are competitive with $Λ$C…

Cosmology-independent Photon Mass Limits from Localized Fast Radio Bursts by using Artificial Neural Networks
Jing-Yu Ran, Bao Wang, Jun-Jie Wei
https://arxiv.org/abs/2404.17154 <…

Cosmology-independent Photon Mass Limits from Localized Fast Radio Bursts by using Artificial Neural Networks
A hypothetical photon mass, $m_γ$, can produce a frequency-dependent vacuum dispersion of light, which leads to an additional time delay between photons with different frequencies when they propagate through a fixed distance. The dispersion measure--redshift measurements of fast radio bursts (FRBs) have been widely used to constrain the rest mass of the photon. However, all current studies analyzed the effect of the frequency-dependent dispersion for massive photons in the standard $Λ$CDM cos…

Cosmology-independent Photon Mass Limits from Localized Fast Radio Bursts by using Artificial Neural Networks
Jing-Yu Ran, Bao Wang, Jun-Jie Wei
https://arxiv.org/abs/2404.17154 <…

Cosmology-independent Photon Mass Limits from Localized Fast Radio Bursts by using Artificial Neural Networks
A hypothetical photon mass, $m_γ$, can produce a frequency-dependent vacuum dispersion of light, which leads to an additional time delay between photons with different frequencies when they propagate through a fixed distance. The dispersion measure--redshift measurements of fast radio bursts (FRBs) have been widely used to constrain the rest mass of the photon. However, all current studies analyzed the effect of the frequency-dependent dispersion for massive photons in the standard $Λ$CDM cos…

$H_0$-tension in the classical limit of Big Bang quantum cosmology
Maurice H. P. M. van Putten (INAF-OAS, Sejong University)
https://arxiv.org/abs/2403.10865

$H_0$-tension in the classical limit of Big Bang quantum cosmology
$Λ$CDM is challenged by observational tensions between late- and early-time cosmology, most dramatically in the Hubble constant $H_0$. $Λ$CDM hereby falls short as an effective infra-red (IR) limit of quantum cosmology. Consistency with general relativity in an effective dark energy $Λ=α_pΛ_0\sim H^2/c^2$ obtains from an IR-coupling $α_p\sim \hbar$ to the bare cosmological constant $Λ_0\sim 1/\hbar$, where $\hbar$ is the Planck constant. A path integral formulation with gauged total phas…

From infinite to infinitesimal: Using the Universe as a dataset to probe Casimir corrections to the vacuum energy from fields inhabiting the dark dimension
Luis A. Anchordoqui, Ignatios Antoniadis, Dieter Lust, Neena T. Noble, Jorge F. Soriano
https://arxiv.org/abs/2404.17334

From infinite to infinitesimal: Using the Universe as a dataset to probe Casimir corrections to the vacuum energy from fields inhabiting the dark dimension
Promptly after high-resolution experiments harbinger the field of precision cosmology low- and high-redshift observations abruptly gave rise to a tension in the measurement of the present-day expansion rate of the Universe ($H_0$) and the clustering of matter ($S_8$). The statistically significant discrepancies between the locally measured values of $H_0$ and $S_8$ and the ones inferred from observations of the cosmic microwave background assuming the canonical $Λ$ cold dark matter (CDM) cosmo…

From infinite to infinitesimal: Using the Universe as a dataset to probe Casimir corrections to the vacuum energy from fields inhabiting the dark dimension
Luis A. Anchordoqui, Ignatios Antoniadis, Dieter Lust, Neena T. Noble, Jorge F. Soriano
https://arxiv.org/abs/2404.17334

From infinite to infinitesimal: Using the Universe as a dataset to probe Casimir corrections to the vacuum energy from fields inhabiting the dark dimension
Promptly after high-resolution experiments harbinger the field of precision cosmology low- and high-redshift observations abruptly gave rise to a tension in the measurement of the present-day expansion rate of the Universe ($H_0$) and the clustering of matter ($S_8$). The statistically significant discrepancies between the locally measured values of $H_0$ and $S_8$ and the ones inferred from observations of the cosmic microwave background assuming the canonical $Λ$ cold dark matter (CDM) cosmo…

Attention-based Neural Network Emulators for Multi-Probe Data Vectors Part I: Forecasting the Growth-Geometry split
Kunhao Zhong, Evan Saraivanov, James Caputi, Vivian Miranda, Supranta S. Boruah, Tim Eifler, Elisabeth Krause
https://arxiv.org/abs/2402.17716

Attention-based Neural Network Emulators for Multi-Probe Data Vectors Part I: Forecasting the Growth-Geometry split
We present a new class of machine-learning emulators that accurately model the cosmic shear, galaxy-galaxy lensing, and galaxy clustering real space correlation functions in the context of Rubin Observatory year one simulated data. To illustrate its capabilities in forecasting models beyond the standard $Λ$CDM, we forecast how well LSST Year 1 data will be able to probe the consistency between geometry $Ω^{\rm geo}_\mathrm{m}$ and growth $Ω^{\rm growth}_\mathrm{m}$ dark matter densities in t…

This https://arxiv.org/abs/2308.16183 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Late Time Modification of Structure Growth and the S8 Tension
The $S_8$ tension between low-redshift galaxy surveys and the primary CMB signals a possible breakdown of the $Λ$CDM model. Recently differing results have been obtained using low-redshift galaxy surveys and the higher redshifts probed by CMB lensing, motivating a possible time-dependent modification to the growth of structure. We investigate a simple phenomenological model in which the growth of structure deviates from the $Λ$CDM prediction at late times, in particular as a simple function o…

This https://arxiv.org/abs/2403.09221 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Betti Functionals as a Probe for Cosmic Topology
The question of the global topology of the Universe (cosmic topology) is still open. In the $Λ$CDM concordance model it is assumed that the space of the Universe possesses the trivial topology of $\mathbb{R}^3$ and thus that the Universe has an infinite volume. As an alternative, we study in this paper one of the simplest non-trivial topologies given by a cubic 3-torus describing a universe with a finite volume. To probe cosmic topology, we analyse certain structure properties in the cosmic mi…

Sound Horizon Independent Constraints on Early Dark Energy: The Role of Supernova Data
Joshua A. Kable, Vivian Miranda
https://arxiv.org/abs/2403.11916 htt…

Sound Horizon Independent Constraints on Early Dark Energy: The Role of Supernova Data
We assess the consistency of cosmological models that alter the size of the sound horizon at last scattering to resolve the Hubble tension with data from ACT + Planck CMB lensing, Big Bang Nucleosynthesis, and supernova data from Pantheon or Pantheon+. We use early dark energy (EDE) as an example model but conclude that the results apply to other similar models. We constrain $Λ$CDM and EDE with these data finding that while they can constrain $Λ$CDM very tightly, EDE opens up the parameter sp…

Accelerated inference on accelerated cosmic expansion: New constraints on axion-like early dark energy with DESI BAO and ACT DR6 CMB lensing
Frank J. Qu, Kristen M. Surrao, Boris Bolliet, J. Colin Hill, Blake D. Sherwin, Hidde T. Jense
https://arxiv.org/abs/2404.16805

Accelerated inference on accelerated cosmic expansion: New constraints on axion-like early dark energy with DESI BAO and ACT DR6 CMB lensing
The early dark energy (EDE) extension to $Λ$CDM has been proposed as a candidate scenario to resolve the "Hubble tension". We present new constraints on the EDE model by incorporating new data from the Dark Energy Spectroscopic Instrument (DESI) Baryon Acoustic Oscillation (BAO) survey and CMB lensing measurements from the Atacama Cosmology Telescope (ACT) DR6 and \textit{Planck} NPIPE data. We do not find evidence for EDE. The maximum fractional contribution of EDE to the total energy density…

This https://arxiv.org/abs/2305.07049 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Insights from HST into Ultra-Massive Galaxies and Early-Universe Cosmology
The early-science observations made by the James Webb Space Telescope (JWST) have revealed an excess of ultra-massive galaxy candidates that appear to challenge the standard cosmological model ($Λ$CDM). Here, we argue that any modifications to $Λ$CDM that can produce such ultra-massive galaxies in the early Universe would also affect the UV galaxy luminosity function (UV LF) inferred from the Hubble Space Telescope (HST). The UV LF covers the same redshifts ($z\approx 7-10$) and host-halo mas…

This https://arxiv.org/abs/2310.01491 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

First constraints on Non-minimally coupled Natural and Coleman-Weinberg inflation in the light of massive neutrino self-interactions and Planck+BICEP/Keck
In this work, for the first time in literature, we compare the predictions of non-minimally coupled Natural and Coleman-Weinberg potentials in the $n_s-r$ plane against the constraints from the latest cosmological data in an extended $Λ$CDM model where we include non-standard self-interactions among massive neutrinos, mediated by a heavy scalar or vector boson. For the inflationary potentials, we consider two different formulations in gravity that are non-minimally coupled to the scalar field …

Reconstructing Cosmic History: JWST-Extended Mapping of the Hubble Flow from z$ \sim $0 to z$ \sim$7.5 with HII Galaxies
Ricardo Ch\'avez, Roberto Terlevich, Elena Terlevich, Ana Gonz\'alez-Mor\'an, David Fern\'andez-Arenas, Fabio Bresolin, Manolis Plionis, Spyros Basilakos, Ricardo Amor\'in, Mario Llerena
https://

Reconstructing Cosmic History: JWST-Extended Mapping of the Hubble Flow from z$ \sim $0 to z$ \sim$7.5 with HII Galaxies
Over twenty years ago, Type Ia Supernovae (SNIa) [arXiv:astro-ph/9805201, arXiv:astro-ph/9812133] observations revealed an accelerating Universe expansion, suggesting a significant dark energy presence, often modelled as a cosmological constant, $Λ$. Despite its pivotal role in cosmology, the standard $Λ$CDM model remains largely underexplored in the redshift range between distant SNIa and the Cosmic Microwave Background (CMB). This study harnesses the James Webb Space Telescope's advanced ca…

This https://arxiv.org/abs/2401.15080 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

A proposal to improve the accuracy of cosmological observables and address the Hubble tension problem
(abridged)Cosmological observational programs often compare their data not only with $Λ$CDM, but also with extensions applying dynamical models of dark energy (DDE), with a time-dependent equation of state (EoS) parameter $w$. We found a degeneracy in the customary computational procedure for the expansion history, once DDE models are applied. This degeneracy provides an infinite number of cosmological models reproducing the Planck-measured CMB spectrum. Moreover, this degeneracy biases the co…

This https://arxiv.org/abs/2309.12292 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Constraining dark energy cosmologies with spatial curvature using Supernovae JWST forecasting
Recent cosmological tensions, in particular, to infer the local value of the Hubble constant $H_0$, have developed new independent techniques to constrain cosmological parameters in several cosmologies. Moreover, even when the concordance Cosmological Constant Cold Dark Matter ($Λ$CDM) model has been well constrained with local observables, its physics has shown deviations from a flat background. Therefore, to explore a possible deviation from a flat $Λ$CDM model that could explain the $H_0$ …

Can Early Dark Energy be Probed by the High-Redshift Galaxy Abundance?
Weiyang Liu, Hu Zhan, Yan Gong, Xin Wang
https://arxiv.org/abs/2402.14339 https://…

Can Early Dark Energy be Probed by the High-Redshift Galaxy Abundance?
The Hubble tension and $σ_{8}$ tension are two of the major issues of the standard $Λ$ Cold Dark Matter ($Λ$CDM) model. The analysis of the Cosmic Microwave Background (CMB) data acquired by the Atacama Cosmology Telescope (ACT) and the large-scale ($\ell\lesssim1300$) Planck Telescope manifest their preference for the Early Dark Energy (EDE) theory, which was set to alleviate the Hubble tension by decreasing the sound horizon $r_{s}$, and gives $H_{0} \approx 72 \ km \ s^{-1} \ Mpc^{-1}$. H…

Can Early Dark Energy be Probed by the High-Redshift Galaxy Abundance?
Weiyang Liu, Hu Zhan, Yan Gong, Xin Wang
https://arxiv.org/abs/2402.14339 https://…

Can Early Dark Energy be Probed by the High-Redshift Galaxy Abundance?
The Hubble tension and $σ_{8}$ tension are two of the major issues of the standard $Λ$ Cold Dark Matter ($Λ$CDM) model. The analysis of the Cosmic Microwave Background (CMB) data acquired by the Atacama Cosmology Telescope (ACT) and the large-scale ($\ell\lesssim1300$) Planck Telescope manifest their preference for the Early Dark Energy (EDE) theory, which was set to alleviate the Hubble tension by decreasing the sound horizon $r_{s}$, and gives $H_{0} \approx 72 \ km \ s^{-1} \ Mpc^{-1}$. H…

Dark Radiation with Baryon Acoustic Oscillations from DESI 2024 and the $H_0$ tension
Itamar J. Allali, Alessio Notari, Fabrizio Rompineve
https://arxiv.org/abs/2404.15220

Dark Radiation with Baryon Acoustic Oscillations from DESI 2024 and the $H_0$ tension
We investigate the presence of extra relativistic degrees of freedom in the early Universe, contributing to the effective number of neutrinos $N_\text{eff}$, as $ΔN_\text{eff}\equiv N_\text{eff}-3.044\geq 0$, in light of the recent measurements of Baryon Acoustic Oscillations (BAO) by the DESI collaboration. We analyze one-parameter extensions of the $Λ$CDM model where dark radiation (DR) is free streaming or behaves as a perfect fluid, due to self-interactions. We report a significant relaxa…

This https://arxiv.org/abs/2312.09814 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Review of Hubble tension solutions with new SH0ES and SPT-3G data
We present an updated analysis of eleven cosmological models that may help reduce the Hubble tension, which now reaches the $6σ$ level when considering the latest SH0ES measurement versus recent CMB and BAO data, assuming $Λ$CDM. Specifically, we look at five classical extensions of $Λ$CDM (with massive neutrinos, spatial curvature, free-streaming or self-interacting relativistic relics, or dynamical dark energy) and six elaborate models featuring either a time-varying electron mass, early d…

This https://arxiv.org/abs/2312.09814 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Review of Hubble tension solutions with new SH0ES and SPT-3G data
We present an updated analysis of eleven cosmological models that may help reduce the Hubble tension, which now reaches the $6σ$ level when considering the latest SH0ES measurement versus recent CMB and BAO data, assuming $Λ$CDM. Specifically, we look at five classical extensions of $Λ$CDM (with massive neutrinos, spatial curvature, free-streaming or self-interacting relativistic relics, or dynamical dark energy) and six elaborate models featuring either a time-varying electron mass, early d…

This https://arxiv.org/abs/2305.16176 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

A Parametric Model for Self-Interacting Dark Matter Halos
We propose a parametric model for studying self-interacting dark matter (SIDM) halos. The model uses an analytical density profile, calibrated using a controlled N-body SIDM simulation that covers the entire gravothermal evolution, including core-forming and -collapsing phases. By normalizing the calibrated density profile, we obtain a universal description for SIDM halos at any evolution phase. The model allows us to infer properties of SIDM halos based on their cold dark matter (CDM) counterp…

Constraining the emergent dark energy models with cosmology-independent observational data
GuangZhen Wang, Xiaolei Li, Nan Liang
https://arxiv.org/abs/2404.14237

Constraining the emergent dark energy models with cosmology-independent observational data
In this work, we investigate the phenomenologically emergent dark energy (PEDE) model and its generalized form, namely the generalized emergent dark energy (GEDE) model, which introduces a free parameter \unboldmath {\( Δ\)} that can discriminate between the \unboldmath{$\mathrmΛ$}CDM model and the PEDE model. Fitting the emergent dark energy (EDE) models with the observational datasets including the cosmology-independent gamma-ray bursts (GRBs) at high-redshift and the observational Hubble d…

Towards a new model-independent calibration of Gamma-Ray Bursts
Arianna Favale, Maria Giovanna Dainotti, Adri\`a G\'omez-Valent, Marina Migliaccio
https://arxiv.org/abs/2402.13115

Towards a new model-independent calibration of Gamma-Ray Bursts
Current data on baryon acoustic oscillations and Supernovae of Type Ia cover up to $z\sim2.5$. These low-$z$ observations play a very important role in the determination of cosmological parameters and have been widely used to constrain the $Λ$CDM and models beyond the standard. To extend this investigation to higher redshifts, Gamma-Ray Bursts (GRBs) stand out as one of the most promising observables since can probe the universe up to $z\sim9.4$. The use of GRB correlations is still a challeng…

This https://arxiv.org/abs/2401.14234 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Velocity acoustic oscillations on Cosmic Dawn 21 cm power spectrum as a probe of small-scale density fluctuations
We investigate the feasibility of using the velocity acoustic oscillations (VAO) features on the Cosmic Dawn 21 cm power spectrum to probe small-scale density fluctuations. In the standard cold dark matter (CDM) model, Pop III stars form in minihalos and affect the 21 cm signal through Ly$α$ and X-ray radiation. Such a process is modulated by the relative motion between dark matter and baryons, generating the VAO wiggles on the 21 cm power spectrum. In the fuzzy or warm dark matter models for …

Testing Tachyon-Dominated Cosmology with Type Ia Supernovae
Samuel H. Kramer, Ian H. Redmount
https://arxiv.org/abs/2403.13859 https://

Testing Tachyon-Dominated Cosmology with Type Ia Supernovae
An open or hyperbolic Friedmann-Robertson-Walker spacetime dominated by tachyonic dark matter can exhibit an ``inflected'' expansion -- initially decelerating, later accelerating -- similar but not identical to that of now-standard $Λ$CDM models dominated by dark energy. The features of the tachyonic model can be extracted by fitting the redshift-distance relation of the model to data obtained by treating Type Ia supernovae as standard candles. Here such a model is fitted to samples of 186 and…

Modeling nonlinear scales with COLA: preparing for LSST-Y1
Jonathan Gordon, Bernardo F. de Aguiar, Jo\~ao Rebou\c{c}as, Guilherme Brando, Felipe Falciano, Vivian Miranda, Kazuya Koyama, Hans A. Winther
https://arxiv.org/abs/2404.12344

Modeling nonlinear scales with COLA: preparing for LSST-Y1
Year 1 results of the Legacy Survey of Space and Time (LSST) will provide tighter constraints on small-scale cosmology, beyond the validity of linear perturbation theory. This heightens the demand for a computationally affordable prescription that can accurately capture nonlinearities in beyond-$Λ$CDM models. The COmoving Lagrangian Acceleration (COLA) method, a cost-effective \textit{N}-body technique, has been proposed as a viable alternative to high-resolution \textit{N}-body simulations fo…

This https://arxiv.org/abs/2402.17492 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

syren-halofit: A fast, interpretable, high-precision formula for the $Λ$CDM nonlinear matter power spectrum
Rapid and accurate evaluation of the nonlinear matter power spectrum, $P(k)$, as a function of cosmological parameters and redshift is of fundamental importance in cosmology. Analytic approximations provide an interpretable solution, yet current approximations are neither fast nor accurate relative to numerical emulators. We use symbolic regression to obtain simple analytic approximations to the nonlinear scale, $k_σ$, the effective spectral index, $n_{\rm eff}$, and the curvature, $C$, which …

This https://arxiv.org/abs/2302.00181 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Dwarf Galaxies United by Dark Bosons
Low mass galaxies in the Local Group are dominated by dark matter and comprise the well studied ``dwarf Spheroidal" (dSph) class, with typical masses of $10^{9-10}M_\odot$ and also the equally numerous ``ultra faint dwarfs" (UFD), discovered recently, that are distinctly smaller and denser with masses of only $10^{7-8}M_\odot$. This bimodality amongst low mass galaxies contrasts with the scale free continuity expected for galaxies formed under gravity, as in the standard Cold Dark Matter (CDM) …

Interacting Scalar fields: Dark Matter--Early Dark Energy
Gabriela Garcia-Arroyo, L. Arturo Ure\~na-L\'opez, J. Alberto V\'azquez
https://arxiv.org/abs/2402.08815

Interacting Scalar fields: Dark Matter--Early Dark Energy
The main aim of this work is to explore the possibility that cold dark matter (CDM) and early dark energy (EDE) can be described by canonical scalar fields that are coupled at the level of its conservation equations. The formalism covers dynamical aspects at the background and linear perturbation levels for an arbitrary coupling function, followed by an example of it. We emphasize the impact of this model on the Matter Power Spectrum and the Cosmic Microwave Background (CMB) spectra, with or wi…