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相关论文: Cosmological Perturbations and the Running Cosmolo…

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The dynamics of density and metric perturbations is investigated for the previously developed model where the decay of the vacuum energy into matter (or vice versa) is due to the renormalization group (RG) running of the cosmological…

广义相对论与量子宇宙学 · 物理学 2010-10-27 Julio C. Fabris , Ilya L. Shapiro , Joan Sola

We carry out a multi-probe self-consistency test of the flat $\Lambda$CDM model with the aim of exploring potential causes of the reported tensions between high- and low-redshift cosmological observations. We divide the model into two…

We investigate the matter density perturbation $\delta_m$ and power spectrum $P(k)$ in the running vacuum model (RVM) with the cosmological constant being a function of the Hubble parameter, given by $\Lambda = \Lambda_0 + 6 \sigma H H_0+…

宇宙学与河外天体物理 · 物理学 2016-11-09 Chao-Qiang Geng , Chung-Chi Lee

We investigate the linear growth rate of cosmological matter density perturbations of a viable f(R) model both numerically and analytically. We find that the growth rate in the scalar-tensor regime can be characterized by a simple analytic…

宇宙学与河外天体物理 · 物理学 2014-11-20 Tatsuya Narikawa , Kazuhiro Yamamoto

We study the evolution of matter density perturbations in the framework of massive conformal gravity (MCG). Starting from the conservation of the energy-momentum tensor, we find the continuity and Euler equations for the conformal perfect…

广义相对论与量子宇宙学 · 物理学 2026-02-03 F. F. Faria , G. S. Silva

In the context of a spatially flat $\Lambda(t)$CDM cosmology, we investigate interacting dark energy (IDE) scenarios characterized by phenomenological interaction terms proportional to the Hubble expansion rate and the dark energy density.…

宇宙学与河外天体物理 · 物理学 2026-02-13 A. A. Escobal , H. A. P. Macedo , J. F. Jesus , R. C. Nunes , J. A. S. Lima

We investigate the matter density fluctuations \delta\rho/\rho for two dark energy (DE) models in the literature in which the cosmological term \Lambda is a running parameter. In the first model, the running LCDM model, matter and DE…

广义相对论与量子宇宙学 · 物理学 2009-04-28 Javier Grande , Reuven Opher , Ana Pelinson , Joan Sola

The standard $\Lambda$CDM cosmological model informed by cosmic microwave background (CMB) anisotropies makes a precise prediction for the growth of matter density fluctuations over cosmic time on linear scales. A variety of cosmological…

宇宙学与河外天体物理 · 物理学 2024-11-14 Mathew S. Madhavacheril

On the basis of a previously established scalar-tensor extension of the $\Lambda$CDM model we develop an effective fluid approach for the matter growth function. This extended $\Lambda$CDM (henceforth $e_{\Phi}\Lambda$CDM) cosmology takes…

宇宙学与河外天体物理 · 物理学 2019-05-01 W. Zimdahl , H. E. S. Velten , W. C. Algoner

The latest cosmological observables analyses seem to converge to a concordant view of the cosmological model: namely the power law Lambda-CDM. The recent WMAP results comfort this new standard model. Nevertheless, some degeneracy in the CMB…

天体物理学 · 物理学 2007-05-23 Marian Douspis

The cosmological constant $\Lambda$ and cold dark matter (CDM) model ($\Lambda\text{CDM}$) is one of the pillars of modern cosmology and is widely used as the de facto theoretical model by current and forthcoming surveys. As the nature of…

宇宙学与河外天体物理 · 物理学 2022-06-08 Rubén Arjona , Alessandro Melchiorri , Savvas Nesseris

A type of exponential correction to General Relativity gives viable modified gravity model of dark energy. The model behaves as $R-2\Lambda$ at large curvature where an effective cosmological constant appears, but it becomes zero in flat…

广义相对论与量子宇宙学 · 物理学 2022-01-13 L. N. Granda

Cosmologies including continuous matter creation are able to reproduce the main properties of the standard $\Lambda$CDM model, in particular in cases where the particle and entropy production rates are equal. These specific models,…

广义相对论与量子宇宙学 · 物理学 2011-03-07 Alain de Roany , J. A. de Freitas Pacheco

We investigate the growth of matter fluctuations in holographic dark energy cosmologies. First we use an overall statistical analysis involving the latest observational data in order to place constraints on the cosmological parameters. Then…

宇宙学与河外天体物理 · 物理学 2015-12-16 Ahmad Mehrabi , Spyros Basilakos , Mohammad Malekjani , Zahra Davari

In the era of precision cosmology, the cosmological constant $\Lambda$ gives quite an accurate description of the evolution of the Universe, but it is still plagued with the fine-tuning problem and the cosmic coincidence problem. In this…

宇宙学与河外天体物理 · 物理学 2021-04-27 Srijita Sinha , Narayan Banerjee

In this paper we calculate the linear perturbations of the cosmological redshift drift. We show explicitly that our expressions are gauge-invariant and compute the power spectrum of the redshift drift perturbations and its correlations with…

宇宙学与河外天体物理 · 物理学 2023-11-30 Pedro Bessa , Ruth Durrer , Dennis Stock

We use recently published redshift space distortion measurements of the cosmological growth rate, f sigma_8(z), to examine whether the linear evolution of perturbations in the R_h=ct cosmology is consistent with the observed development of…

宇宙学与河外天体物理 · 物理学 2018-09-21 Fulvio Melia

This paper reviews selected aspects of the growth of cosmological structure, covering the following general areas: (1) expected characteristics of linear density perturbations according to various candidate theories for the origin of…

天体物理学 · 物理学 2007-05-23 J. A. Peacock

The current standard cosmological model is constructed within the framework of general relativity with a cosmological constant $\Lambda$, which is often associated with dark energy, and phenomenologically explains the accelerated cosmic…

广义相对论与量子宇宙学 · 物理学 2023-06-27 Jiamin Hou , Julian Bautista , Maria Berti , Carolina Cuesta-Lazaro , César Hernández-Aguayo , Tilman Tröster , Jinglan Zheng

We investigate the evolution of cosmic structures within the framework of modified gravity, specifically focusing on theories described by the function $f(R, L_m)$, where $R$ is the Ricci scalar and $L_m$ is the matter Lagrangian. This…

广义相对论与量子宇宙学 · 物理学 2025-07-08 G. K. Goswami , J. P. Saini
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