English
Related papers

Related papers: Non-homogeneity-driven Universe acceleration

200 papers

A class of Stephani cosmological models as a prototype of non-homogeneous universe is considered. The non-homogeneity can lead to accelerated evolution which is now observed from the SNIa data. Three samples of type Ia supernovae obtained…

Astrophysics · Physics 2009-11-10 Wlodzimierz Godlowski , Jerzy Stelmach , Marek Szydlowski

In this paper, the dynamical behavior of the accelerated expansion of the universe is discussed within the framework of $f(T)$ gravity, considering power law functional form of $ f(T)=\alpha (-T)^{n}$. Two distinct redshift-dependent…

General Relativity and Quantum Cosmology · Physics 2025-08-29 Shivank Pal , Romanshu Garg , Gyan Prakash Singh , Gauree Shanker

In view of late-time cosmic acceleration, a dark energy cosmological model is revisited wherein Einstein's cosmological constant is considered as a candidate of dark energy. Exact solution of Einstein field equations (EFEs) is derived in a…

General Relativity and Quantum Cosmology · Physics 2019-11-22 S. K. J. Pacif , Md Salahuddin Khan , L. K. Paikroy , Shalini Singh

We present a special case of the Stephani solution with spherical symmetry while considering different values of spatial curvature. We investigate the dynamics of the universe evolution in our model, build the R--T-regions for the resulting…

General Relativity and Quantum Cosmology · Physics 2020-02-06 I. Bormotova , E. Kopteva , M. Churilova , Z. Stuchlik

Experimental tests of homogeneous-universe classical standpoint cosmology are proposed after presentation of conceptual considerations that encourage this radical departure from the standard model. Among predictions of the new model are…

General Relativity and Quantum Cosmology · Physics 2007-05-23 G. F. Chew

We use the redshift-magnitude relation, as derived by D\c{a}browski (1995), for the two exact non-uniform pressure spherically symmetric Stephani universes with the observer positioned at the center of symmetry, to test the agreement of…

Astrophysics · Physics 2009-10-30 M. P. Dabrowski , M. A. Hendry

We investigate a fourth order model of gravity, having a free length parameter, and no cosmological constant or dark energy. We consider cosmological evolution of a flat Friedmann universe in this model for the case that the length…

General Relativity and Quantum Cosmology · Physics 2015-10-14 Shreya Banerjee , Nilesh Jayswal , Tejinder P. Singh

The deceleration parameter q as the diagnostic of the cosmological accelerating expansion is investigated. By expanding the luminosity distance to the fourth order of redshift and the so-called y-redshift in two redshift bins and fitting…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Ronggen Cai , Zhongliang Tuo

In this study, we have demonstrated the expansion history of an axially symmetric Bianchi type-I model of the universe. Our model as of now presents an accelerating universe, which had been in the decelerating phase in the past. Roles of…

General Relativity and Quantum Cosmology · Physics 2022-11-30 Vinod Kumar Bhardwaj , Archana Dixit , Rita Rani , G. K. Goswami , Anirudh Pradhan

This study investigates the cosmological dynamics of an accelerating universe within the framework of teleparallel gravity using an exponential f(T) functional form. To obtain exact cosmological solutions, a hybrid scale factor is employed…

General Relativity and Quantum Cosmology · Physics 2026-05-27 Rajalakshmi Jena , Vishal M C , Sankarsan Tarai

In this paper, we present a cosmological model within the framework of symmetric teleparallel gravity, focusing on $f(Q)$ gravity, where $Q$ represents the non-metricity scalar. Utilizing cosmological datasets, we derive an accelerating…

General Relativity and Quantum Cosmology · Physics 2024-08-09 S. A. Narawade , S. H. Shekh , B. Mishra , Wompherdeiki Khyllep , Jibitesh Dutta

By relaxing the constraint of adiabatic universe used in most cosmological models, we have shown that the new approach provides a better fit to the supernovae Ia redshift data with a single parameter, the Hubble constant $H_0$, than the…

General Physics · Physics 2018-10-31 Rajendra P. Gupta

We investigate isotropic and homogeneous cosmological scenarios in the scalar-tensor theory of gravity with non-minimal derivative coupling of a scalar field to the curvature given by the term $(\zeta/H_0^2) G^{\mu\nu}\nabla_\mu\phi…

General Relativity and Quantum Cosmology · Physics 2023-06-02 Sergey V. Sushkov , Rafkat Galeev

We show in a model-independent way that the inhomogeneous cosmological class II Stephani model fulfills both the the cosmological holographic principle, and that the entropy is increasing with time. By this we mean the result does not…

General Relativity and Quantum Cosmology · Physics 2020-02-25 Daniele Gregoris , Yen Chin Ong , Bin Wang

We perform a number of inter-related cosmographic fits to the legacy05 and gold06 supernova datasets. We pay particular attention to the influence of both statistical and systematic uncertainties, and also to the extent to which the choice…

General Relativity and Quantum Cosmology · Physics 2007-07-31 Celine Cattoen , Matt Visser

In this paper, we have investigated some accelerating cosmological models at the backdrop of an anisotropic metric in an extended gravity theory. Two viable cosmological models one with a little rip behaviour and the other with a hyperbolic…

General Relativity and Quantum Cosmology · Physics 2020-09-23 B. Mishra , S. K. Tripathy

We probe the cosmic expansion scenario within the framework of $f(R, L_{m})$ gravity by employing a well-motivated functional form of $f(R, L_{m}) = \frac{R}{2} + L_{m}^{\lambda}$. Specifically, we introduce three novel cosmological models…

General Relativity and Quantum Cosmology · Physics 2026-05-27 Khomesh R. Patle , G. P. Singh

Understanding the evolution of dark energy poses a significant challenge in modern cosmology, as it is responsible for the universe's accelerated expansion. In this study, we focus on a specific $f(T)$ cosmological model and analyze its…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-14 A. Zhadyranova , M. Koussour , S. Bekkhozhayev , V. Zhumabekova , J. Rayimbaev

Among various phenomenological $\Lambda$ models, a time-dependent model $\dot \Lambda\sim H^3$ is selected here to investigate the $\Lambda$-CDM cosmology. Using this model the expressions for the time-dependent equation of state parameter…

General Relativity and Quantum Cosmology · Physics 2011-01-25 Saibal Ray , Maxim Khlopov , Utpal Mukhopadhyay , Partha Pratim Ghosh

We have probed a cosmological model in $f(R)$-gravity, which is a cubic equation in scalar curvature $R$. The terms arise due to nonlinear $f(R)$ function are treated as energy due to curvature inspired geometry. As a result, we find…

General Relativity and Quantum Cosmology · Physics 2023-05-03 G. K. Goswami , Rita Rani , Harshna Balhara , J. K. Singh
‹ Prev 1 2 3 10 Next ›