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By comparing the results from numerical microlensing simulations to the observed long-term variability of quasars, strong upper limits on the cosmological density of compact objects in the 0.0001-1 solar mass range may in principle be…

Astrophysics · Physics 2009-11-07 Erik Zackrisson , Nils Bergvall

Within the context of Rastall gravity, we investigate the hydrostatic equilibrium and dynamical stability against radial pulsations of compact stars, where a free parameter $\beta$ measures the deviations from General Relativity (GR). We…

General Relativity and Quantum Cosmology · Physics 2024-07-01 Juan M. Z. Pretel , Clésio E. Mota

An expression for rotational velocity of a test particle around the central mass in the invariant plane is derived. For this, a line element of Schwarzschild de-Sitter space-time is used to study the effect of cosmological constant…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-09 B. Aryal , R. Pandey , N. Baral , U. Khanal , W. Saurer

In this study we obtain interior solutions and investigate structural properties of isotropic compact stars in the framework of four-dimensional regularized Einstein-Gauss-Bonnet (4DEGB) gravity. For stellar matter content, we adopt a…

General Relativity and Quantum Cosmology · Physics 2026-01-21 G. Panotopoulos , Á. Rincón , I. Lopes

Motivated by the recent discovery of a compact object with mass in the range $2.5{-}2.67\, \mathrm{M}_\odot$ in the binary merger GW190814, we revisit the question of the maximum mass of neutron stars (NSs). We use a Markov Chain Monte…

High Energy Astrophysical Phenomena · Physics 2021-06-22 Daniel A. Godzieba , David Radice , Sebastiano Bernuzzi

We consider the classical theory of a gravitational field with spin 2 and non-vanishing (Pauli-Fierz) mass in flat spacetime, coupled to electromagnetism and point particles. We establish the law of light propagation and calculate the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Matteo Carrera , Domenico Giulini

This paper investigates the existence and properties of stable, uniformly rotating star-planet systems, i.e. mass ratio is sufficiently small. It is modeled by the Euler-Poisson equations. Following the framework established by McCann for…

Analysis of PDEs · Mathematics 2026-04-22 Hangsheng Chen

The Minimal theory of Massive Gravity (MTMG) is endowed non-linearly with only two tensor modes in the gravity sector which acquire a non-zero mass. On a homogeneous and isotropic background the theory is known to possess two branches: the…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-15 Antonio De Felice , Shinji Mukohyama , Masroor C. Pookkillath

By using elementary astrophysical concepts, we show that for any self-luminous astrophysical object, the ratio of radiation energy density inside the body (rho_r) and the baryonic energy density (rho_0) may be crudely approximated, in the…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Abhas Mitra

Linearized gravity in the Very Special Relativity (VSR) framework is considered. We prove that this theory allows for a non-zero graviton mass $m_g$ without breaking gauge invariance nor modifying the relativistic dispersion relation. We…

General Relativity and Quantum Cosmology · Physics 2023-09-07 Jorge Alfaro , Alessandro Santoni

Utilizing various gauges of the radial coordinate, we give a General Relativistic (GR) description of static spherically symmetric spacetimes with a massive point source and vacuum outside this singularity. We show that in GR there exists a…

General Relativity and Quantum Cosmology · Physics 2019-11-13 Plamen P. Fiziev

We construct gravitational atoms including self-gravity, obtaining solutions of the Einstein-Klein-Gordon equations for a scalar field surrounding a non-rotating black hole in a quasi-stationary approximation. We resolve the region near the…

General Relativity and Quantum Cosmology · Physics 2025-10-23 Miguel Alcubierre , Juan Barranco , Argelia Bernal , Juan Carlos Degollado , Alberto Diez-Tejedor , Miguel Megevand , Darío Núñez , Olivier Sarbach

A special class of higher curvature theories of gravity, Ricci Cubic Gravity (RCG), in general d dimensional space-time has been investigated in this paper. We have used two different approaches, the linearized equations of motion and…

High Energy Physics - Theory · Physics 2017-09-13 Ahmad Ghodsi , Farzaneh Najafi

The dRGT massive gravity represent a comprehensive theory which properly describes massive graviton field. Latterly, the exact spherical solutions are identified for the black hole in the dRGT massive gravity theory. In this paper, we…

General Relativity and Quantum Cosmology · Physics 2023-04-14 Hamed Hadi , Amin Rezaei Akbarieh , Pouneh Safarzadeh Ilkhchi

We consider the consequences of applying general relativity to the description of the dynamics of a galaxy, given the observed flattened rotation curves. The galaxy is modeled as a stationary axially symmetric pressure-free fluid. In spite…

Astrophysics · Physics 2010-10-27 F. I. Cooperstock , S. Tieu

I derive general conditions in order to explain the origin of the Vainshtein radius inside dRGT. The set of equations, which I have called "Vainshtein" conditions are extremal conditions of the dynamical metric ($g_{\mu\nu}$) containing all…

General Relativity and Quantum Cosmology · Physics 2014-12-30 Ivan Arraut

We give the detailed derivation of the fully covariant form of the quadratic action and the derived linear equations of motion for a massive graviton in an arbitrary background metric (which were presented in arXiv:1410.8302 [hep-th]). Our…

High Energy Physics - Theory · Physics 2015-04-20 Laura Bernard , Cedric Deffayet , Mikael von Strauss

We investigate how stable circular orbits around a main compact object appear depending on the presence of a second one by using the Majumudar--Papapetrou dihole spacetime, which consists of the two extremal Reissner--Nordstr\" om black…

General Relativity and Quantum Cosmology · Physics 2019-11-07 Keisuke Nakashi , Takahisa Igata

In this letter, we consider the six-dimensional Kaluza-Klein models with spherical compactification of the internal space. Here, we investigate the case of bare gravitating compact objects with the dustlike equation of state $\hat p_0=0$ in…

General Relativity and Quantum Cosmology · Physics 2012-09-03 Maxim Eingorn , Alexander Zhuk

We explore the maximum mass limit of strange stars in quadratic curvature gravity with the non-minimal matter coupling. The characteristic parameters of the quadratic curvature coupling and the non-minimal matter coupling imply the…

General Relativity and Quantum Cosmology · Physics 2026-04-24 Debadri Bhattacharjee , Pradip Kumar Chattopadhyay , Kazuharu Bamba