中文
相关论文

相关论文: $S_8$ increases with effective redshift in $\Lambd…

200 篇论文

In the paper, we consider two models in which dark energy is coupled with either dust matter or dark matter, and discuss the conditions that allow more time for structure formation to take place at high redshifts. These models are expected…

宇宙学与河外天体物理 · 物理学 2021-03-08 Shulei Cao , Tong-Jie Zhang , Xinya Wang , Tingting Zhang

Emerging high redshift cosmological probes, in particular quasars (QSOs), show a preference for larger matter densities, $\Omega_{m} \approx 1$, within the flat $\Lambda$CDM framework. Here, using the Risaliti-Lusso relation for…

We present a comprehensive analysis of the $\Lambda_{\rm s}$CDM model, which explores the recent conjecture suggesting a rapid transition of the Universe from anti-de Sitter vacua to de Sitter vacua (viz., the cosmological constant switches…

宇宙学与河外天体物理 · 物理学 2023-07-21 Ozgur Akarsu , Eleonora Di Valentino , Suresh Kumar , Rafael C. Nunes , J. Alberto Vazquez , Anita Yadav

In this paper, we study the normalised characteristic scale of transition to cosmic homogeneity, $\mathcal{R}_H/d_V$, as a cosmological probe. We use a compilation of SDSS galaxy samples, comprising more than $10^6$ galaxies in the redshift…

宇宙学与河外天体物理 · 物理学 2021-06-18 Pierros Ntelis , Adam James Hawken , Stephanie Escoffier , Anne Ealet , Andre Tilquin

The idea of a rapid sign-switching cosmological constant (mirror AdS-dS transition) in the late universe at $z\sim1.7$, known as the $\Lambda_{\rm s}$CDM model, has significantly improved the fit to observational data and provides a…

In this work, we investigate a cosmological scenario with a time-dependent cosmological constant $\Lambda$(t) within the spatially flat Friedmann-Lema\^itre-Robertson-Walker (FLRW) framework. Here we study a power-law $\Lambda(t)$CDM model…

广义相对论与量子宇宙学 · 物理学 2025-10-28 Archana Dixit , Manish Yadav , Anirudh Pradhan , M. S. Barak

The key probes of the growth of large-scale structure are its rate $f$ and amplitude $\sigma_8$. Redshift space distortions in the galaxy power spectrum allow us to measure only the combination $f\sigma_8$, which can be used to constrain…

宇宙学与河外天体物理 · 物理学 2020-10-14 Louis Perenon , Stéphane Ilić , Roy Maartens , Alvaro de la Cruz-Dombriz

The standard $\Lambda$CDM model is recently reported to deviate from the high-redshift Hubble diagram of type Ia supernovae (SNe) and quasars (QSOs) at $\sim4\sigma$ confidence level. In this work, we combine the PAge approximation (a…

宇宙学与河外天体物理 · 物理学 2022-10-26 Zhuoyang Li , Lu Huang , Junchao Wang

We present a Bayesian analysis of cosmological parameter constraints from early- and late-universe observations, focusing on the matter density parameter ($\Omega_m$) and the amplitude of matter fluctuations ($\sigma_8$) within the…

宇宙学与河外天体物理 · 物理学 2026-01-13 Manjeet Kunwar , Nabin Bhusal , Manil Khatiwada , Niraj Dhital

A well-known problem of the $\Lambda$CDM model is the tension between the relatively high level of clustering, as quantified by the parameter $\sigma_8$, found in cosmic microwave background experiments and the smaller one obtained from…

宇宙学与河外天体物理 · 物理学 2019-01-04 Bruno J. Barros , Luca Amendola , Tiago Barreiro , Nelson J. Nunes

We present improved constraints on an interacting vacuum model using updated astronomical observations including the first data release from Planck. We consider a model with one dimensionless parameter, $\alpha$, describing the interaction…

宇宙学与河外天体物理 · 物理学 2014-07-09 Yuting Wang , David Wands , Gong-Bo Zhao , Lixin Xu

Many late time approaches for the solution of the Hubble tension use late time smooth deformations of the Hubble expansion rate $H(z)$ of the Planck18/$\Lambda$CDM best fit to match the locally measured value of $H_0$ while effectively…

宇宙学与河外天体物理 · 物理学 2021-05-14 G. Alestas , L. Perivolaropoulos

Given the persistence of various tensions in the "Cosmic Concordance" -- such as the "Hubble Tension", and possible departures from LambdaCDM time evolution -- seen from combinations of complementary data sets (e.g., Cosmic Microwave…

宇宙学与河外天体物理 · 物理学 2026-02-19 Brett Bochner , Aiden Jin

We analyze how predictions of cosmological models depend on a choice of described observational data, restrictions on flatness, and how this choice can alleviate the $H_0$ tension. These effects are demonstrated in the $w$CDM model in…

广义相对论与量子宇宙学 · 物理学 2020-02-11 G. S. Sharov , E. S. Sinyakov

Magnitude predictions of $\Lambda$CDM, as parametrized by the Planck collaboration, are not consistent with the supernova data of the whole Pantheon+ sample even when, in order to take into account the uncertainty about its value, the…

宇宙学与河外天体物理 · 物理学 2024-12-03 Yves-Henri Sanejouand

We apply a tension metric $Q_\textrm{UDM}$, the update difference in mean parameters, to understand the source of the difference in the measured Hubble constant $H_0$ inferred with cosmic microwave background lensing measurements from the…

宇宙学与河外天体物理 · 物理学 2021-02-02 W. L. Kimmy Wu , Pavel Motloch , Wayne Hu , Marco Raveri

Constraints on the cosmological concordance model parameters from observables at different redshifts are usually obtained using the locally measured value of the gravitational constant $G_N$. Here we relax this assumption, by considering…

宇宙学与河外天体物理 · 物理学 2022-06-28 Ziad Sakr , Domenico Sapone

We explore the late time cosmological dynamics of the Universe within the framework of $f(Q,\mathcal{L}_{m})$ gravity by considering the specific form $f(Q, \mathcal{L}_m)=-Q+2\mathcal{L}_m+\gamma$. To describe the cosmic pressure…

广义相对论与量子宇宙学 · 物理学 2025-08-08 Amit Samaddar , S. Surendra Singh

The recent Planck Legacy 2018 release has confirmed the presence of an enhanced lensing amplitude in CMB power spectra compared to that predicted in the standard $\Lambda$CDM model. A closed universe can provide a physical explanation for…

宇宙学与河外天体物理 · 物理学 2019-11-07 Eleonora Di Valentino , Alessandro Melchiorri , Joseph Silk

We obtain the reduced CMB data $\{l_A, R, z_*\}$ from WMAP9, WMAP9+BICEP2, Planck+WP and Planck+WP+BICEP2 for the $\Lambda$CDM and $w$CDM models with or without spatial curvature. We then use these reduced CMB data in combination with…

宇宙学与河外天体物理 · 物理学 2015-07-06 Rong-Gen Cai , Zong-Kuan Guo , Bo Tang