English
Related papers

Related papers: Gravity's Rainbow and Compact Stars

200 papers

Two approaches to the study of cosmological density perturbations in modified theories of Palatini gravity have recently been discussed. These utilise, respectively, a generalisation of Birkhoff's theorem and a direct linearization of the…

General Relativity and Quantum Cosmology · Physics 2010-10-27 Kotub Uddin , James E Lidsey , Reza Tavakol

We investigate possible signatures of quantum gravity which could be tested with current and future gravitational-wave (GW) observations. In particular, we analyze how quantum gravity can influence the GW luminosity distance, the time…

General Relativity and Quantum Cosmology · Physics 2019-10-08 Gianluca Calcagni , Sachiko Kuroyanagi , Sylvain Marsat , Mairi Sakellariadou , Nicola Tamanini , Gianmassimo Tasinato

Low energy imprints of modifications to general relativity are often found in pressure balance equations inside stars. These modifications are then amenable to tests via astrophysical phenomena, using observational effects in stellar…

General Relativity and Quantum Cosmology · Physics 2023-07-07 Debojyoti Garain , Pritam Banerjee , Shaswata Chowdhury , Tapobrata Sarkar

Scalar-tensor theories are among the most promising alternatives to general relativity that have been developed to account for some long standing issues in our understanding of gravity. Some of these theories predict the existence of a…

High Energy Astrophysical Phenomena · Physics 2021-01-06 J. Soldateschi , N. Bucciantini , L. Del Zanna

Cosmological departures from general relativity offer a possible explanation for the cosmic acceleration. To linear order, these departures (quantified by the model-independent parameter $\varpi$, referred to as a `gravitational slip')…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-05 Scott F. Daniel

We study slow-roll inflation and the generation of primordial fluctuations in $F(T)$ gravity's rainbow. We obtain the second order action for scalar and tensor perturbations and then calculate the primordial power spectrum for them. Thus,…

General Relativity and Quantum Cosmology · Physics 2022-02-18 Yoelsy Leyva , Carlos Leiva , Giovanni Otalora , Joel Saavedra

In this work, we study several extensions of the higher curvature modification of $R^{2}$ inflation in the context of gravity's rainbow. We modify the $(R+R^{2})$ model by adding an $f_{1}R^3$-term, an $f_{2}R^4$-term, and an…

General Relativity and Quantum Cosmology · Physics 2024-08-05 Jureeporn Yuennan , Phongpichit Channuie , Davood Momeni

This study deals with the formation and evolution of a strange star in the Krori Barua Rainbow spacetime from collapsing charged stringy quark matter. The dynamical variables are explored from the field equations, taking into account the…

General Relativity and Quantum Cosmology · Physics 2024-01-26 Wasib Ali , Umber Sheikh

We comment on some implications of theories with large compactification radii and TeV-scale quantum gravity. These include the behavior of high-energy gravitational scattering cross sections and consequences for ultra-high-energy cosmic…

High Energy Physics - Phenomenology · Physics 2009-10-31 Shmuel Nussinov , Robert Shrock

The equation of state for compact stars is reviewed with special emphasis on the role of strange hadrons, strange dibaryons and strange quark matter. Implications for the properties of compact stars are presented. The importance of neutron…

Astrophysics · Physics 2008-11-26 Jurgen Schaffner-Bielich

Starting from an heuristic approach to the semiclassical limit in loop quantum gravity, the construction of effective Hamiltonians describing Planck length corrections to the propagation of photons and spin 1/2 fermions, leading to modified…

High Energy Physics - Phenomenology · Physics 2016-11-09 Luis F. Urrutia

We carry out a simple analysis of (n+3)-dimensional gravity in the context of recent work on 'large' supplementary dimensions and deduce a formula for the expected compactification radius for the n additional dimensions in the universe, as…

Nuclear Theory · Physics 2010-11-19 Alejandro Frank , Piet van Isacker , Joaquin Gomez-Camacho

The gravitational-radiation-induced inspiral of a binary system of compact objects is considered. A scheme is described to model the regime in which the gravitational interaction is too strong to use weak-field approximation methods, but…

General Relativity and Quantum Cosmology · Physics 2007-05-23 John T. Whelan

This paper reviews the physics of stars, the type, structure, evolution and stability. Simple thermodynamics and statistical mechanics are used to show the inner working of white dwarf and neutron stars. The major concentration of the paper…

Popular Physics · Physics 2024-03-21 Anuj Chaudhri

Magnetic fields play a crucial role in many astrophysical scenarios and, in particular, are of paramount importance in the emission mechanism and evolution of Neutron Stars (NSs). To understand the role of the magnetic field in compact…

High Energy Astrophysical Phenomena · Physics 2015-06-18 A. G. Pili , N. Bucciantini , L. Del Zanna

We consider the effects of rotations on the calculation of some thermodynamical quantities like the free energy, internal energy and entropy. In ordinary gravity, when we evaluate the density of states of a scalar field close to a black…

General Relativity and Quantum Cosmology · Physics 2019-07-09 Remo Garattini

We investigate a class of theories involving a symmetric two-tensor field in Minkowski spacetime with a potential triggering spontaneous violation of Lorentz symmetry. The resulting massless Nambu-Goldstone modes are shown to obey the…

General Relativity and Quantum Cosmology · Physics 2015-05-13 Alan Kostelecky , Robertus Potting

In this work we investigate the equilibrium configurations of white dwarfs in a modified gravity theory, na\-mely, $f(R,T)$ gravity, for which $R$ and $T$ stand for the Ricci scalar and trace of the energy-momentum tensor, respectively.…

General Relativity and Quantum Cosmology · Physics 2017-12-20 G. A. Carvalho , R. V. Lobato , P. H. R. S. Moraes , José D. V. Arbañil , R. M. Marinho , E. Otoniel , M. Malheiro

We give a linear response relation for perturbations in relativistic stars and classify them in terms of implicit and induced perturbations. The focus in this article is on the induced perturbations which may arise due to internal sources…

General Relativity and Quantum Cosmology · Physics 2022-11-04 Seema Satin

We consider a broad class of interactions between radiation and a light scalar field, including both conformal and disformal couplings. Such a scalar field potentially acts on cosmological scales as dark energy and could also appear in…

High Energy Astrophysical Phenomena · Physics 2015-10-07 Philippe Brax , Pierre Brun , Denis Wouters