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Related papers: Running vacuum model in non-flat universe

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The decaying vacuum model (DV), treating dark energy as a varying vacuum, has been studied well recently. The vacuum energy decays linearly with the Hubble parameter in the late-times, $\rho_\Lambda(t) \propto H(t)$, and produces the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 M. L. Tong , H. Noh

The spatial curvature ($\Omega_K$) of the Universe is one of the most fundamental quantities that could give a link to the early universe physics. In this paper we develop an approximate method to compute the nonlinear matter power…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-19 Ryo Terasawa , Ryuichi Takahashi , Takahiro Nishimichi , Masahiro Takada

The search for a physical model which explains the observed recent acceleration of the universe is a compelling task of modern fundamental cosmology. Recently Fernandes \textit{et al.} presented low redshift observational constraints on a…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-01 C. J. A. P. Martins , J. S. J. S. Oliveira , D. A. R. Pinheiro

The behavior of the constants, G,c,h,a,e,m and Lambda, considering them as variable, in the framework of a flat cosmological model with FRW symmetries described by a bulk viscous fluid and considering mechanisms of adiabatic matter creation…

General Relativity and Quantum Cosmology · Physics 2014-11-17 J. A. Belinchon

The existence of inhomogeneities in the observed Universe modifies the distance-redshift relations thereby affecting the results of cosmological tests in comparison to the ones derived assuming spatially uniform models. By modeling the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 V. C. Busti , R. C. Santos , J. A. S. Lima

In this paper, we investigate the freezing quintessence scenario in late-time cosmic expansion using a non-linear $f(R, L_m)$ gravity model, $f(R,L_m)=\frac{R}{2}+L_m^\alpha$, where $\alpha$ is a free parameter. We consider a solution for…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-17 Yerlan Myrzakulov , M. Koussour , A. Caliskan , E. Güdekli , S. Muminov , J. Rayimbaev

The $\Lambda$CDM framework offers a remarkably good description of our universe with a very small number of free parameters, which can be determined with high accuracy from currently available data. However, this does not mean that the…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-22 Yves Zolnierowski , Alain Blanchard

The concordance (LambdaCDM) model reproduces the main current cosmological observations assuming the validity of general relativity at all scales and epochs, the presence of cold dark matter, and of a cosmological constant, equivalent to a…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-08 Guido Risaliti , Elisabeta Lusso

We examine the properties of the scale invariant cosmological models, also making the specific hypothesis of the scale invariance of the empty space at large scales. Numerical integrations of the cosmological equations for different values…

General Relativity and Quantum Cosmology · Physics 2016-05-25 Andre Maeder

We have considered a cosmological model of the FRW universe with variable $G$ and $\Lambda$. The solutions have been obtained for flat model with particular form of cosmological constant. The cosmological parameters have also been obtained…

General Relativity and Quantum Cosmology · Physics 2011-03-31 Mubasher Jamil , Ujjal Debnath

The holographic $\Lambda(t)$CDM model in a non-flat universe is studied in this paper. In this model, to keep the form of the stress-energy of the vacuum required by general covariance, the holographic vacuum is enforced to exchange energy…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-26 Jing-Fei Zhang , Yang-Yang Li , Ying Liu , Sheng Zou , Xin Zhang

Recent studies of QFT in cosmological spacetime indicate that the speeding up of the present universe may not just be associated with a rigid cosmological term but with a running one that evolves with the expansion rate:…

General Relativity and Quantum Cosmology · Physics 2025-04-04 Joan Solà Peracaula , Cristian Moreno-Pulido , Alex González-Fuentes

Recent analyses in the literature suggest that the concordance $\Lambda$CDM model with rigid cosmological term, $\Lambda=$const., may not be the best description of the cosmic acceleration. The class of "running vacuum models", in which…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-29 Joan Sola , Adria Gomez-Valent , Javier de Cruz Perez

Inferring spatial curvature of the Universe with high-fidelity is a longstanding interest in cosmology. However, the strong degeneracy between dark energy equation-of-state parameter $w$ and curvature density parameter $\Omega_{\rm K}$ has…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-11 Yang Hu , Suhail Dhawan

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…

General Relativity and Quantum Cosmology · Physics 2010-10-27 Julio C. Fabris , Ilya L. Shapiro , Joan Sola

We present constraints on extensions to the flat $\Lambda$CDM cosmological model by varying the spatial curvature $\Omega_K$, the sum of the neutrino masses $\sum m_\nu$, the dark energy equation of state parameter $w$, and the Hu-Sawicki…

Keeping in mind the current picture of an accelerating and flat Universe, some specific dynamical models of the cosmological term $\Lambda$ have been selected for investigating the nature of dark energy. Connecting the free parameters of…

Astrophysics · Physics 2008-11-26 Saibal Ray , Utpal Mukhopadhyay , Xin-He Meng

We perform a general test of the $\Lambda{\rm CDM}$ and $w {\rm CDM}$ cosmological models by comparing constraints on the geometry of the expansion history to those on the growth of structure. Specifically, we split the total matter energy…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-25 Uendert Andrade , Dhayaa Anbajagane , Rodrigo von Marttens , Dragan Huterer , Jailson Alcaniz

With the entrance of cosmology in its new era of high precision experiments, low- and high-redshift observations set off tensions in the measurements of both the present-day expansion rate ($H_0$) and the clustering of matter ($S_8$). We…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-16 Eleonora Di Valentino , Supriya Pan , Weiqiang Yang , Luis A. Anchordoqui

Spatial curvature is one of the fundamental cosmological parameters that is routinely constrained from observations. The forward modelling of observations, in particular of large-scale structure, often relies on large cosmological…

General Relativity and Quantum Cosmology · Physics 2026-03-10 Julian Adamek , Renan Boschetti