中文
相关论文

相关论文: Barotropic FRW cosmologies with a Dirac-like param…

200 篇论文

It is known that barotropic FRW equations written in the conformal time variable can be reduced to simple linear equations for an exponential function involving the conformal Hubble rate. Here, we show that an interesting class of…

数学物理 · 物理学 2015-02-13 Haret C. Rosu , Stefan C. Mancas , Pisin Chen

Simple linear second-order differential equations have been written down for FRW cosmologies with barotropic fluids by Faraoni. His results have been extended by Rosu, who employed techniques belonging to nonrelativistic supersymmetry to…

广义相对论与量子宇宙学 · 物理学 2016-08-31 H. C. Rosu , O. Cornejo , M. Reyes , D. Jimenez

Barotropic FRW cosmologies are presented from the standpoint of nonrelativistic supersymmetry. First, we reduce the barotropic FRW system of differential equations to simple harmonic oscillator differential equations. Employing the…

广义相对论与量子宇宙学 · 物理学 2007-05-23 H. C. Rosu , P. Ojeda-May

We apply the technique of standard supersymmetric factorization for any q factor ordering in the Wheeler-DeWitt (WDW) equation for barotropic Friedmann-Robertson-Walker (FRW) minisuperspace model, including the cosmological term. The…

数学物理 · 物理学 2009-11-10 J. Socorro , M. A. Reyes , F. A. Gelbert

This paper has studied five-dimensional FRW cosmological models for k=-1,0,1in the presence of two perfect fluids namely ordinary baryonic fluid and a bizarre creating dark energy within the framework of Lyra's manifold (Lyra 1951). We have…

广义相对论与量子宇宙学 · 物理学 2023-12-22 Syed Sabanam , Kangujam Priyokumar Singh

In the case of barotropic FRW cosmologies, the Hubble parameter in conformal time is the solution of a simple Riccati equation of constant coefficients. We consider these cosmologies in the framework of nonrelativistic supersymmetry that…

广义相对论与量子宇宙学 · 物理学 2015-03-17 Haret C. Rosu , Kira V. Khmelnytskaya

In this work, I present a generalized linear Hubble law for a barotropic spherically symmetric inhomogeneous spacetime, which is in principle compatible with the acceleration of the cosmic expansion obtained as a result of high redshift…

广义相对论与量子宇宙学 · 物理学 2014-11-17 J. -F. Pascual-Sánchez

To find more deliberate f(R,T) cosmological solutions, we proceed our previous paper further by studying some new aspects of the considered models via investigation of some new cosmological parameters/quantities to attain the most…

广义相对论与量子宇宙学 · 物理学 2017-05-23 Hamid Shabani , Mehrdad Farhoudi

In this paper, we propose extended Chaplygin gas equation of state for which it recovers barotropic fluid with quadratic equation of state. We use numerical method to investigate the behavior of some cosmological parameters such as scale…

广义相对论与量子宇宙学 · 物理学 2014-09-17 B. Pourhassan , E. O. Kahya

The dynamics of perfect fluid as a source in the context of modified gravity, specifically $f(Q,T)$ gravity, are examined within the Friedmann-Lema\^itre-Robertson-Walker (FLRW) cosmological model. This gravity is a generic function of the…

广义相对论与量子宇宙学 · 物理学 2024-08-02 S. H. Shekh , Anirudh Pradhan , S. P. Gaikwad , K. R. Mule

In this work, we study a cosmological model of spatially homogeneous and isotropic accelerating universe which exhibits a transition from deceleration to acceleration. For this, Friedmann Robertson Walker(FRW) metric is taken and Hybrid…

广义相对论与量子宇宙学 · 物理学 2021-08-02 G. K. Goswami , Anirudh Pradhan , Meena Mishra , A. Beesham

Entropic cosmology with the R\'{e}nyi entropy of the apparent horizon $S_R=(1/\alpha)\ln(1+\alpha S_{BH})$, where $S_{BH}$ is the Bekenstein--Hawking entropy, is studied. By virtue of the thermodynamics-gravity correspondence a model of…

综合物理 · 物理学 2026-05-04 S. I. Kruglov

In the context of f(R, T) gravity theory for the flat Friedmann Lemaitre Robertson Walker (FLRW) model, the accelerating expansion of the universe is investigated using a specific form of the emergent Hubble parameter. Datasets from H(z),…

广义相对论与量子宇宙学 · 物理学 2025-01-16 N. Myrzakulov , S. H. Shekh , Anirudh Pradhan , Archana Dixit

The Riccati equation for the Hubble parameter H of barotropic FRW cosmologies in conformal time for \kappa \neq 0 spatial geometries and in comoving time for the \kappa =0 geometry, respectively, is generalized to odd Grassmannian time…

广义相对论与量子宇宙学 · 物理学 2009-11-07 H. C. Rosu , J. Torres

This paper investigates the cosmological implications of the modified gravity framework known as $f(R,\Sigma, T)$ gravity, focusing on its potential to unify and extend current cosmological models. The theory, introduced by Bakry and…

广义相对论与量子宇宙学 · 物理学 2025-03-04 N. Myrzakulov , S. H. Shekh , Anirudh Pradhan

In this paper we present cosmological constraints on several well-known $f(R)$ models, but also on a new class of models that are variants of the Hu-Sawicki one of the form $f(R)=R-\frac{2\Lambda}{1+b\;y(R,\Lambda)}$, that interpolate…

宇宙学与河外天体物理 · 物理学 2018-01-29 Judit Pérez-Romero , Savvas Nesseris

In this paper, we considered the study of Friedmann-Robertson-Walker (FRW) model in the framework of $f(Q,T)$ gravity, an extension of symmetric teleparallel gravity, recently defined by Y. Xu et al. \cite{Xu}. The non-linear model…

广义相对论与量子宇宙学 · 物理学 2021-05-05 Nisha Godani , Gauranga C Samanta

The horizon of a flat Friedmann--Robertson--Walker (FRW) universe is considered to be dynamic when the Hubble parameter $H$ and the Hubble radius $r_{H}$ vary with time, unlike for de Sitter universes. To clarify the thermodynamics on a…

广义相对论与量子宇宙学 · 物理学 2023-10-17 Nobuyoshi Komatsu

Here, we consider new nonadditive entropy of the apparent horizon $S_K=S_{BH}/(1+\gamma S_{BH})$ with $S_{BH}$ being the Bekenstein--Hawking entropy. This is an alternative of the R\'{e}nyi and Tsallis entropies, that allows us, by…

综合物理 · 物理学 2025-11-18 S. I. Kruglov

In this paper we place new constraints on a f(R) modified gravity model recently proposed by Hu and Sawicki. After checking that the Hu and Sawicki model produces a viable cosmology, i.e. a matter dominated epoch followed by a late-time…

宇宙学与河外天体物理 · 物理学 2009-07-09 Matteo Martinelli , Alessandro Melchiorri , Luca Amendola
‹ 上一页 1 2 3 10 下一页 ›