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Related papers: Oscillating phantom in $F(R)$ gravity

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We investigate the realization of two bouncing paradigms, namely of the superbounce and the loop quantum cosmological ekpyrosis, in the framework of various modified gravities. In particular, we focus on the $F(R)$, $F(G)$ and $F(T)$…

General Relativity and Quantum Cosmology · Physics 2015-08-25 S. D. Odintsov , V. K. Oikonomou , Emmanuel N. Saridakis

We investigate how the cosmological Equation of State can be used for scrutinizing extended theories of gravity, in particular, the Palatini $f(R)$ gravity. Specifically, the approach consists, at first, in investigating the effective…

General Relativity and Quantum Cosmology · Physics 2024-02-27 S. Camera , S. Capozziello , L. Fatibene , A. Orizzonte

We investigate the Einstein static universe (ESU) and the emergent universe scenario in the framework of Ho\v{r}ava-Lifshitz-like $F(R)$ gravity. We first perform a dynamical analysis in the phase space, and amongst others we show that a…

General Relativity and Quantum Cosmology · Physics 2016-06-10 M. Khodadi , Y. Heydarzade , F. Darabi , E. N. Saridakis

We derive asymptote solution of a homogeneous and isotropic universe governed by the quadratic form of the field equation of $f(T)$ gravity. We explain how the higher order of the torsion can provide an origin for late accelerated phase of…

General Relativity and Quantum Cosmology · Physics 2015-06-30 G. G. L. Nashed

In this article we perform dynamical analysis of a broad class of barotropic fluids in the spatially curved Friedmann-Robertson-Walker (FRW) spacetime background without considering the cosmological constant. The first part of our study…

General Relativity and Quantum Cosmology · Physics 2020-03-04 Morteza Kerachian , Giovanni Acquaviva , Georgios Lukes-Gerakopoulos

We reconstruct an explicit model of modified gravity in which a crossing of the phantom divide can be realized. It is shown that the (finite-time) Big Rip singularity appears in the model of modified gravity (i.e., in the so-called Jordan…

High Energy Physics - Theory · Physics 2013-05-29 Kazuharu Bamba , Chao-Qiang Geng , Shin'ichi Nojiri , Sergei D. Odintsov

We examine an unexplored quantum phenomenon we call oscillatory localization, where a discrete-time quantum walk with Grover's diffusion coin jumps back and forth between two vertices. We then connect it to the power dissipation of a…

Quantum Physics · Physics 2016-12-21 Andris Ambainis , Krišjānis Prūsis , Jevgēnijs Vihrovs , Thomas G. Wong

We calculate the f(R) gravity function in the dual gravity description of the quintessence model with a quadratic (Linde) scalar potential and a positive cosmological constant. We find that in the large curvature regime relevant to chaotic…

High Energy Physics - Theory · Physics 2018-05-09 Sergei V. Ketov , Natsuki Watanabe

The gravitational phase shift of neutrino oscillation can be discussed in the framework of f(R)-gravity. We show that the shift of quantum mechanical phase can depend on the given f(R)-theory that we choose. This fact is general and could…

General Relativity and Quantum Cosmology · Physics 2015-05-18 S. Capozziello , M. De Laurentis , D. Vernieri

The current transit universe model is a precise solution to the equations of a new type of gravity theory called metric-affine $f(R,T,Q,T_m)$ gravity proposed in [Herko et al. \textit{Phys. Dark Univ.} \textbf{34} (2021) 100886]. This…

General Relativity and Quantum Cosmology · Physics 2026-02-19 Dinesh Chandra Maurya , Harjit Kumar

We propose a bigravity analogue of the $F(R)$ gravity. Our construction is based on recent ghost-free massive bigravity where additional scalar fields are added and the corresponding conformal transformation is implemented. It turns out…

High Energy Physics - Theory · Physics 2015-06-05 Shin'ichi Nojiri , Sergei D. Odintsov

We reconstruct $F(R)$ gravity models with exponential and power-law forms of the scale factor in which bounce cosmology can be realized. We explore the stability of the reconstructed models with analyzing the perturbations from the…

High Energy Physics - Theory · Physics 2014-01-10 Kazuharu Bamba , Andrey N. Makarenko , Alexandr N. Myagky , Shin'ichi Nojiri , Sergei D. Odintsov

In this work we shall study the late-time dynamics of several $F(R)$ gravity models. By appropriately expressing the field equations in terms of the redshift and of a statefinder function, we shall solve numerically the field equations…

General Relativity and Quantum Cosmology · Physics 2022-09-07 V. K. Oikonomou , Ifigeneia Giannakoudi

The properties of a fictitious, fermionic, many-body system based on the complex zeros of the Riemann zeta function are studied. The imaginary part of the zeros are interpreted as mean-field single-particle energies, and one fills them up…

Chaotic Dynamics · Physics 2007-05-23 P. Leboeuf , A. G. Monastra , O. Bohigas

This work deals with $F(T)$ gravity models driven by real scalar fields with usual and phantom dynamics. We illustrate the results with examples of current interest, and we find some analytical solutions for scale factors and scalar fields.…

General Relativity and Quantum Cosmology · Physics 2010-06-22 K. K. Yerzhanov , Sh. R. Myrzakul , I. I. Kulnazarov , R. Myrzakulov

The study conducted in this research paper utilizes the $f(Q,T)$ gravity, where $Q$ represents non-metricity and $T$ represents the trace of the energy-momentum tensor, to investigate the accelerated expansion of the universe. To complete…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-17 M. Koussour , N. Myrzakulov , J. Rayimbaev , A. Errehymy , Orhan Donmez

The dark energy crossing of the cosmological constant boundary (the transition between the quintessence and phantom regimes) is described in terms of the implicitly defined dark energy equation of state. The generalizations of the models…

Astrophysics · Physics 2009-11-13 Hrvoje Stefancic

In the present paper we generate a set of solutions describing the interior of a compact star under $f(R,T)$ theory of gravity which admits conformal motion. We consider the equation of state (EOS) $p=\omega\rho$ with $0<\omega<1$ for the…

General Relativity and Quantum Cosmology · Physics 2016-12-20 Amit Das , Farook Rahaman , B. K. Guha , Saibal Ray

Recently it has been shown that the cosmological dynamics of covariant $f(Q)$ gravity depend on different affine connections. In this paper, two specific $f(Q)$ models are investigated with SNe+CC+BAO+QSO observational data, and the spatial…

General Relativity and Quantum Cosmology · Physics 2023-10-24 Jiaming Shi

We describe the accelerated expansion of the late-time universe using a generalized equation of state (EoS) when account is taken of bulk viscosity. We assume a homogeneous and isotropic Friedmann-Robertson-Walker spacetime. Solutions of…

General Relativity and Quantum Cosmology · Physics 2019-08-05 I. Brevik , A. N. Makarenko , A. V. Timoshkin
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