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相关论文: $f(\mathcal{G},\mathrm{\textit{T}})$ Gravity Bounc…

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In this paper, we consider a gravitational action containing a combination of the Ricci scalar, $R$, and the topological Gauss--Bonnet term, $G$. Specifically, we study the cosmological features of a particular class of modified gravity…

广义相对论与量子宇宙学 · 物理学 2023-03-15 Francesco Bajardi , Rocco D'Agostino

In this paper, in an extended theory of gravity, we have presented bouncing cosmological model at the backdrop of an isotropic, homogeneous space-time, in presence of general relativistic hydrodynamics (GRH). The scale factor has been…

广义相对论与量子宇宙学 · 物理学 2023-03-29 A. Y. Shaikh , Sankarsan Tarai , S. K. Tripathy , B. Mishra

Here we propose the extended modified gravity theory named as $f(R,G,\mathcal{T})$ gravity where $R$ is the Ricci scalar, $G$ is the Gauss-Bonnet invariant and $\mathcal{T}$ is the trace of the stress-energy tensor. We derive the…

广义相对论与量子宇宙学 · 物理学 2020-12-02 Ujjal Debnath

We consider the possibility to produce a bouncing universe in the framework of scalar-tensor gravity models in which the scalar field potential may be negative, and even unbounded from below. We find a set of viable solutions with nonzero…

广义相对论与量子宇宙学 · 物理学 2015-07-15 B. Boisseau , H. Giacomini , D. Polarski , A. A. Starobinsky

We present a bounce universe in modified $f(Q,C)$ gravity considering linear as well as exponential form of gravity. Bounce cosmological models are introduced to remove the singularity problem of the early universe. A new quadratic boundary…

广义相对论与量子宇宙学 · 物理学 2025-08-07 Bhaswati Mandal , B. C. Paul

In this work by using a numerical analysis, we investigate in a quantitative way the late-time dynamics of scalar coupled $f(R,\mathcal{G})$ gravity. Particularly, we consider a Gauss-Bonnet term coupled to the scalar field coupling…

广义相对论与量子宇宙学 · 物理学 2022-07-27 S. D. Odintsov , V. K. Oikonomou , F. P. Fronimos

Einstein-Gauss-Bonnet (EGB) model is recently restudied in order to analyze new consequences in gravitation, modifying appropriately the Einstein-Hilbert action. The consequences in EGB cosmology are mainly geometric, with higher order…

宇宙学与河外天体物理 · 物理学 2021-03-02 Miguel A. García-Aspeitia , A. Hernández-Almada

Theoretical arguments and cosmological observations suggest that Einstein's theory of general relativity needs to be modified at high energies. One of the best motivated higher-curvature extensions of general relativity is…

广义相对论与量子宇宙学 · 物理学 2017-08-04 Laura Sberna

A scalar-tensor theory of gravity is formulated in which $G$ and particle masses are allowed to vary. The theory yields a globally static cosmological model with no evolutionary timescales, no cosmological coincidences, and no flatness and…

综合物理 · 物理学 2015-10-01 Meir Shimon

This paper analyzes the possibility of bouncing and non-bouncing universes in the framework of four-dimensional Einstein-Gauss-Bonnet (4D-EGB) gravity, corresponding respectively to negative and positive coupling constants $\lambda$ of the…

宇宙学与河外天体物理 · 物理学 2024-06-11 H. Khodabakhshi , M. Farhang , H. Lü

$f(P)$ gravity is a novel extension of ECG in which the Ricci scalar in the action is replaced by a function of the curvature invariant $P$ which represents the contractions of the Riemann tensor at the cubic order \cite{p}. The present…

广义相对论与量子宇宙学 · 物理学 2022-03-29 Snehasish Bhattacharjee

Some models within the framework of Gauss-Bonnet gravities are considered in the presence of a non-minimally coupled scalar field. By imposing a particular constraint on the scalar field coupling, an extension of the called…

广义相对论与量子宇宙学 · 物理学 2022-07-19 Sergei D. Odintsov , Diego Saez-Chillon Gomez , German S. Sharov

In this paper, the dynamical behavior of the accelerated expansion of the universe is studied within the framework of $f(T)$ gravity by considering a well-motivated functional form of $f(T)$. A specific form of the Hubble parameter is…

广义相对论与量子宇宙学 · 物理学 2026-03-20 Khomesh R. Patle , G. P. Singh

$f(T)$ cosmology has shown promise in explaining aspects of cosmic evolution. In this work, we analyze constraints on leading models of $f(T)$ gravity in the context of the recently released Pantheon+ data set, together with comparisons…

广义相对论与量子宇宙学 · 物理学 2023-05-22 Rebecca Briffa , Celia Escamilla-Rivera , Jackson Levi Said , Jurgen Mifsud

We investigate the validity of the generalized second law (GSL) of gravitational thermodynamics in the framework of f(T) modified teleparallel gravity. We consider a spatially flat FRW universe containing only the pressureless matter. The…

广义相对论与量子宇宙学 · 物理学 2012-04-12 K. Karami , A. Abdolmaleki

We investigate the cosmological evolution in a new modified teleparallel theory, called $f(T,B)$ gravity, which is formulated by connecting both $f(T)$ and $f(R)$ theories with a boundary term $B$. Here, $T$ is the torsion scalar in…

综合物理 · 物理学 2018-11-14 M. Zubair , Saira Waheed , M. Atif Fayyaz , Iftikhar Ahmad

We examine the cosmological dynamics of Einstein-Gauss-Bonnet gravity models in a four-dimensional spatially flat FLRW metric. These models are described by $f\left( R,\mathcal{G}\right) =f\left( R+\mu \mathcal{G}\right) $ theory of…

广义相对论与量子宇宙学 · 物理学 2025-12-10 Nikolaos Dimakis , Alex Giacomini , Genly Leon , Andronikos Paliathanasis , Ekaterina Pozdeeva , Sergey Vernov

We explore the possibility of realizing a non-singular bounce in the early universe within the framework of modified gravity with spacetime torsion. In Einstein Cartan theory, torsion is embedded in the spacetime by adding an antisymmetric…

广义相对论与量子宇宙学 · 物理学 2026-01-21 Sonej Alam , Somasri Sen , Soumitra Sengupta

We derive conditions under which f(G) gravity models, whose Lagrangian densities f are written in terms of a Gauss-Bonnet term G, are cosmologically viable. The most crucial condition to be satisfied is that f_GG, the second derivative of f…

高能物理 - 理论 · 物理学 2009-04-18 Antonio De Felice , Shinji Tsujikawa

In the last dozen years a wide and variegated mass of observational data revealed that the universe is now expanding at an accelerated rate. In the absence of a well-based theory to interpret the observations, cosmography provides…

宇宙学与河外天体物理 · 物理学 2015-09-30 Ester Piedipalumbo , Enrica Della Moglie , Roberto Cianci