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Related papers: Holographic Isotropisation in Gauss-Bonnet Gravity

200 papers

We consider cosmological topologically massive gravity at the chiral point with positive sign of the Einstein-Hilbert term. We demonstrate the presence of a negative energy bulk mode that grows linearly in time. Unless there are physical…

High Energy Physics - Theory · Physics 2010-05-12 Daniel Grumiller , Niklas Johansson

The background field equations for homogeneous and isotropic spacetime are derived in conformal scalar-tensor gravity. The background temporal evolution is entirely driven by the dynamical evolution of the scalar field, i.e. particle…

General Physics · Physics 2018-10-12 Meir Shimon

Cosmological solutions for a pressureless fluid in the Brans-Dicke theory exhibit asymptotical accelerated phase for some range of values of the parameter $\omega$, interpolating a matter dominated phase and an inflationary phase. The…

Astrophysics · Physics 2010-12-09 J. C. Fabris , S. V. B. Goncalves , R. de Sa Ribeiro

In this study, we investigated the effects of incorporating barotropic fluids on cosmological solutions within the general relativity (GR) framework. We proposed a modified version of the barotropic fluid with the EoS, $p=\zeta _0 \rho…

General Relativity and Quantum Cosmology · Physics 2025-04-29 Rajdeep Mazumdar , Mrinnoy M. Gohain , Kalyan Bhuyan

We study string theory duals of the expanding boost invariant conformal gauge theory plasmas at strong coupling. The dual supergravity background is constructed as an asymptotic late-time expansion, corresponding to equilibration of the…

High Energy Physics - Theory · Physics 2008-11-26 Paolo Benincasa , Alex Buchel , Michal P. Heller , Romuald A. Janik

In this paper we study (3+1) dimensional holographic superconductors in quasi-topological gravity which is recently proposed by R. Myers {\it et.al.}. Through both analytical and numerical analysis, we find in general the condensation…

High Energy Physics - Theory · Physics 2011-01-05 Xiao-Mei Kuang , Wei-Jia Li , Yi Ling

We consider a non-standard generalized model of gravity coupled to a neutral scalar "inflaton" as well as to the fields of the electroweak bosonic sector. The essential new ingredient is employing two alternative non-Riemannian space-time…

General Relativity and Quantum Cosmology · Physics 2017-09-18 Eduardo Guendelman , Emil Nissimov , Svetlana Pacheva

Corrections are computed to the classical static isotropic solution of general relativity, arising from non-perturbative quantum gravity effects. A slow rise of the effective gravitational coupling with distance is shown to involve a…

High Energy Physics - Theory · Physics 2008-11-26 Herbert W. Hamber , Ruth M. Williams

We introduce a new method designed for Bayesian inference of the angular power spectrum of the Gravitational Wave Background (GWB) anisotropy. This scheme works with time-series data and can optionally incorporate the cross-correlations…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-19 Chi Tian , Ran Ding , Xiao-Xiao Kou

A fluid description for collisionless magnetized plasmas that takes into account the effect of cyclotron resonance has been developed. Following the same approach as the Landau fluid closure, the heat flux components associated with…

Plasma Physics · Physics 2021-04-13 Taiki Jikei , Takanobu Amano

Brane Gas Cosmology (BGC) is an approach to unifying string theory and cosmology in which matter is described by a gas of strings and branes in a dilaton gravity background. The Universe is assumed to start out with all spatial dimensions…

High Energy Physics - Theory · Physics 2009-11-07 Scott Watson , Robert H. Brandenberger

We analyze the spectrum of cosmic microwave background (CMB) anisotropies in the timescape cosmology: a potentially viable alternative to homogeneous isotropic cosmologies without dark energy. We exploit the fact that the timescape…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-18 M. Ahsan Nazer , David L. Wiltshire

We perform a joint likelihood analysis of the power spectra of the 2dF Galaxy Redshift Survey (2dFGRS) and the cosmic microwave background (CMB) anisotropies under the assumptions that the initial fluctuations were adiabatic, Gaussian and…

We study anisotropic Bianchi-I cosmology, incorporating quantum gravitational corrections into the Einstein equation through the scale-dependent Newton coupling and cosmological term, as determined by the flow equation of the effective…

General Relativity and Quantum Cosmology · Physics 2025-12-03 Chiang-Mei Chen , Akihiro Ishibashi , Rituparna Mandal , Nobuyoshi Ohta

In the present paper, we discuss the role of gravitational decoupling to isotropize the anisotropic solution of Einstein's field equations in the context of the complete geometric deformation (CGD) approach and its influence on the…

General Relativity and Quantum Cosmology · Physics 2022-02-09 S. K. Maurya , Riju Nag

In this paper, we have derived the field equations in an extended theory of gravity in an anisotropic space time background and in the presence of magnetic field. The physical and geometrical parameters of the models are determined with…

General Relativity and Quantum Cosmology · Physics 2022-07-19 Sankarsan Tarai , Fakhereh Md. Esmaeili , B. Mishra , S. K. Tripathy

We evaluate reflected entropy in certain anisotropic boundary theories dual to nonrelativistic geometries using holography. It is proposed that this quantity is proportional to the minimal area of the entanglement wedge cross section. Using…

High Energy Physics - Theory · Physics 2025-01-23 Mohammad Javad Vasli , M. Reza Mohammadi Mozaffar , Komeil Babaei Velni , Mohammad Sahraei

Classical higher-derivative gravity is investigated in the context of the holographic renormalization group (RG). We parametrize the Euclidean time such that one step of time evolution in (d+1)-dimensional bulk gravity can be directly…

High Energy Physics - Theory · Physics 2009-11-07 Masafumi Fukuma , So Matsuura

Solutions to the field equations of the Nonsymmetric Gravitational Theory with $g_[i0] = 0$ are obtained for the homogeneous, plane-symmetric, time-dependent case, both in vacuum and in the presence of a perfect fluid. Cosmological…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Pierre Savaria

The present work is related to anisotropic cosmological evolution in metric $f(R)$ theory of gravity. The initial part of the paper develops the general cosmological dynamics of homogeneous anisotropic Bianchi-I spacetime in $f(R)$…

General Relativity and Quantum Cosmology · Physics 2019-01-23 Kaushik Bhattacharya , Saikat Chakraborty