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

200 papers

We study the expansion law of the universe dominated by the oscillating scalar field with non-minimal derivative coupling to gravity as G^{\mu \nu} \partial_{\mu} \phi \partial_{\nu} \phi. In this system the Hubble parameter oscillates with…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Ryusuke Jinno , Kyohei Mukaida , Kazunori Nakayama

In the present paper we study the oscillations of fast rotating neutron stars with realistic equations of state (EoS) within the Cowling approximation. We derive improved empirical relations for gravitational wave asteroseismology with…

Solar and Stellar Astrophysics · Physics 2013-09-04 Daniela D. Doneva , Erich Gaertig , Kostas D. Kokkotas , Christian Krüger

One of the so-called viable modified gravities is analyzed. This kind of gravity theories are characterized by a well behavior at local scales, where General Relativity is recovered, while the modified terms become important at the…

General Relativity and Quantum Cosmology · Physics 2015-06-12 Diego Sáez-Gómez

Current observations seem to mildly favor an evolving dark energy with the equation of state getting across -1. This form of dark energy, dubbed Quintom, is studied phenomenologically in this paper with an oscillating equation of state. We…

Astrophysics · Physics 2008-11-26 Bo Feng , Mingzhe Li , Yun-Song Piao , Xinmin Zhang

In this work we study classical bouncing solutions in the context of $f({\sf R},{\sf T})={\sf R}+h({\sf T})$ gravity in a flat {\sf FLRW} background using a perfect fluid as the only matter content. Our investigation is based on introducing…

General Relativity and Quantum Cosmology · Physics 2018-06-05 Hamid Shabani , Amir Hadi Ziaie

We study particle production of coherently oscillating inflaton in the semiclassical theory of gravity by representing inflaton in coherent and squeezed state formalisms. A comparative study of the inflaton in classical gravity with…

General Relativity and Quantum Cosmology · Physics 2009-11-10 K. K. Venkataratnam , P. K. Suresh

If gravity is fundamentally quantum, any two quantum particles must get entangled with each other due to their mutual interaction through gravity. This phenomenon, dubbed gravity-mediated entanglement, has led to recent efforts of detecting…

General Relativity and Quantum Cosmology · Physics 2023-11-10 Suddhasattwa Brahma , Abhinove Nagarajan Seenivasan

The basic aim of this manuscript is to investigate the cosmological solutions in the context of the modified $f(R, T)$ theory of gravity, where $R$ is the Ricci scalar and $T$ is the trace of the energy-momentum tensor. For our current…

General Relativity and Quantum Cosmology · Physics 2024-03-26 Adnan Malik , Tayyaba Naz , Aimen Rauf , M. Farasat Shamir , Z. Yousaf

The dark energy universe equation of state (EOS) with inhomogeneous,Hubble parameter dependent term is considered. The motivation to introduce such a term comes from time-dependent viscosity considerations and modifications of general…

High Energy Physics - Theory · Physics 2008-11-26 Shin'ichi Nojiri , Sergei D. Odintsov

We investigate the corresponding relation between $f(R)$ gravity and an interacting holographic dark energy. By obtaining conditions needed for some observational evidence such as, positive acceleration expansion of universe, crossing the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Kh. Saaidi , A. Aghamohammadi

This paper investigates the thermodynamic evolution of the universe within the framework of a quadratic equation of state (EoS). Building upon the basis of the quadratic EoS model, as a phenomenological extension to dark energy models, we…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-28 A. Shahriar , M. Abbasiyan-Motlaq , M. Mohsenzadeh , E. Yusofi

We consider a class of metric f(R) modified gravity theories, analyze them in the context of a Friedmann-Robertson-Walker cosmology and confront the results with some of the known constraints imposed by observations. In particular, we focus…

General Relativity and Quantum Cosmology · Physics 2012-06-11 Luisa G. Jaime , Leonardo Patino , Marcelo Salgado

The present work analyzes the various conditions in which there can be a bouncing universe solution in f(R) gravity. In the article an interesting method, to analyze the bouncing FRW solutions in a spatially flat universe using f(R) gravity…

General Relativity and Quantum Cosmology · Physics 2014-12-09 Niladri Paul , Saikat Nil Chakrabarty , Kaushik Bhattacharya

In this paper, we carry out a study of viable cosmological models in $f(R)$-gravity at the background level. We use observable parameters like $\Omega$ and $\gamma$ to form autonomous system of equations and show that the models under…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-28 Amna Ali , Radouane Gannouji , M. Sami , Anjan A. Sen

Here, we peruse cosmological usage of the most promising candidates of dark energy in the framework of f(R) theory. We reconstruct the different f(R) modified gravity models in the spatially flat FRW universe according to the ordinary and…

General Relativity and Quantum Cosmology · Physics 2011-07-18 K. Karami , M. S. Khaledian

We study dynamics of a dark energy component nonminimally coupled to gravity on a moving domain wall. We use this setup to explain late-time accelerated expansion and crossing of the phantom divide line by the equation of state parameter of…

General Relativity and Quantum Cosmology · Physics 2015-05-13 Kourosh Nozari , S. Davood Sadatian

A generic feature of viable $F(R)$ gravity is investigated: It is demonstrated that during the matter dominated era the large frequency oscillations of the effective dark energy may influence the behavior of higher derivatives of the Hubble…

General Relativity and Quantum Cosmology · Physics 2012-12-14 Kazuharu Bamba , Antonio Lopez-Revelles , R. Myrzakulov , S. D. Odintsov , L. Sebastiani

Using coherent and squeezed state formalisms of quantum optics for a minimally coupled non-classical inflaton in the FRW mertic is studied, in semiclassical theory of gravity. The leading order solution for the semiclassical Einstein…

General Relativity and Quantum Cosmology · Physics 2009-02-11 K. K. Venkataratnam , P. K. Suresh

We consider the motion of a harmonically trapped overdamped particle, which is submitted to a self-phoretic force, that is proportional to the gradient of a diffusive field for which the particle itself is the source. In agreement with…

Statistical Mechanics · Physics 2025-01-23 A. Alexandre , L. Anderson , T. Collin-Dufresne , T. Guérin , D. S. Dean

We study forced oscillations of a rod with a body attached to its free end so that the motion of a system is described by two sets of equations, one of integer and the other of the fractional order. To the constitutive equation we associate…

Mathematical Physics · Physics 2013-02-04 Teodor M. Atanackovic , Stevan Pilipovic , Dusan Zorica