English
Related papers

Related papers: Perturbations in Matter Bounce with Non-minimal Co…

200 papers

We construct the most general effective Lagrangian coupling gravity and electromagnetism up to mass dimension 6 by enumerating all possible non-minimal coupling terms respecting both diffeomorphism and gauge invariance. In all, there are…

General Relativity and Quantum Cosmology · Physics 2012-05-09 Yi-Zen Chu , David M. Jacobs , Yifung Ng , Glenn D. Starkman

We study three astrophysical/cosmological consequences of nonminimal couplings to gravity in wavelike vector dark matter. In the nonrelativistic limit, the nonminimal coupling with the lowest mass dimension leads to effective…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-02 Hong-Yi Zhang , Siyang Ling

The Lagrangian perturbation theory on Friedman-Lemaitre cosmologies investigated and solved up to the second order in earlier papers (Buchert 1992, Buchert \& Ehlers 1993) is evaluated up to the third order. On its basis a model for…

Astrophysics · Physics 2015-06-24 Thomas Buchert

Cuscuton Gravity is characterized as a scalar field that can be added to general relativity without introducing any new dynamical degrees of freedom on a cosmological background. Yet, it modifies gravity such that spacetime singularities…

High Energy Physics - Theory · Physics 2025-05-19 Amir Dehghani , Ghazal Geshnizjani , Jerome Quintin

We discuss the propagation of gravitational waves over a non-Riemannian spacetime, when a non-minimal coupling between the geometry and matter is considered in the form of contractions of the energy momentum tensor with the Ricci and…

General Relativity and Quantum Cosmology · Physics 2025-12-16 Flavio Bombacigno , Fabio Moretti , Gonzalo J. Olmo

The linear and quadratic perturbations for a scalar-tensor model with non-minimal coupling to curvature, coupling to the Gauss-Bonnet invariant and non-minimal kinetic coupling to the Einstein tensor are developed. The quadratic action for…

General Relativity and Quantum Cosmology · Physics 2019-09-24 L. N. Granda , D. F. Jimenez

The Einstein-Cartan-Sciama-Kibble theory of gravity naturally extends general relativity to account for the intrinsic spin of matter. Spacetime torsion, generated by spin of Dirac fields, induces gravitational repulsion in fermionic matter…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-03 Nikodem J. Poplawski

Background fields of electromagnetic and gravitational type emerge in the low kinetic energy limit of any regular Lagrangian system and, in particular, in the corresponding limit of any spacetime theory in which the free motion of test…

General Relativity and Quantum Cosmology · Physics 2021-07-14 Paolo Maraner

We propose that at the beginning of the universe gravity existed in a limbo either because it was switched off or because it was only conformally coupled to all particles. This picture can be reverse-engineered from the requirement that the…

General Relativity and Quantum Cosmology · Physics 2015-12-09 Giovanni Amelino-Camelia , Michele Arzano , Giulia Gubitosi , Joao Magueijo

A nonsingular bouncing cosmology in which the scales of interest today exit the Hubble radius in a matter-dominated contracting phase yields an alternative to inflation for producing a scale-invariant spectrum of adiabatic cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2009-05-21 Yi-Fu Cai , Wei Xue , Robert Brandenberger , Xinmin Zhang

Conventional scenarios of purely gravitationally produced dark matter with masses below the Hubble parameter at the end of inflation are in tension with Cosmic Microwave Background (CMB) constraints on the isocurvature power spectrum. We…

High Energy Physics - Phenomenology · Physics 2024-02-15 Marcos A. G. Garcia , Mathias Pierre , Sarunas Verner

The perturbations in the electron number density during recombination contributes to the Cosmic Microwave Background bispectrum through second order terms. Perturbations in the electron density can be a factor of ~5 larger than the baryon…

Astrophysics · Physics 2010-04-21 Rishi Khatri , Benjamin D. Wandelt

We clarify the properties of the behavior of classical cosmological perturbations when the Universe experiences a bounce. This is done in the simplest possible case for which gravity is described by general relativity and the matter content…

High Energy Physics - Theory · Physics 2009-11-10 Jerome Martin , Patrick Peter

The standard nonlinear perturbation theory of the gravitational instability is extended to incorporate the nonlocal bias, redshift-space distortions, and primordial non-Gaussianity. We show that local Eulerian bias is not generally…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-05 Takahiko Matsubara

The problem of nonuniqueness of minimal coupling procedure for Einstein--Cartan (EC) gravity with matter is investigated. It is shown that the predictions of the theory of gravity with fermionic matter can radically change if the freedom of…

General Relativity and Quantum Cosmology · Physics 2015-03-13 Marcin Kazmierczak

The equations governing the evolution of non-minimally coupled scalar matter and the scale factor of a Robertson-Walker universe are derived from a minisuperspace action. As for the minimally coupled case, it is shown that the entire…

General Relativity and Quantum Cosmology · Physics 2009-10-31 G. L. Alberghi , R. Casadio , A. Gruppuso

We consider first order perturbation theory for a non-minimally coupled inflaton field without assuming an adiabatic equation of state. In general perturbations in non-minimally coupled theory may be non-adiabatic. However under the…

High Energy Physics - Phenomenology · Physics 2013-01-10 Abhishek Basak , Jitesh R. Bhatt

The self-consistent system of master equations describing the kinetics of a relativistic non-Abelian plasma, influenced by curvature interactions, is formulated. Non-minimal (curvature induced) coupling is shown to modify all the subsystems…

General Relativity and Quantum Cosmology · Physics 2007-10-04 A. B. Balakin

We consider the modified gravity non-minimally coupled with matter Lagrangian for the description of early-time and late-time universe. Such $F(R)$ ($F(G)$) gravity in the absence of non-minimal coupling is viable theory which passes the…

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

We investigate two classes of non-minimally coupled curvature-matter models in the FLRW universe with a perfect fluid and analyze their cosmological implications using Supernova Ia, Observed Hubble Data, and Baryon Acoustic Oscillation…

General Relativity and Quantum Cosmology · Physics 2024-12-31 Anirban Chatterjee , Akshay Panda , Abhijit Bandyopadhyay