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We study the periapsis shift of a quasi-circular orbit in general static spherically symmetric spacetimes. We derive two formulae in full order with respect to the gravitational field, one in terms of the gravitational mass $m$ and the…

General Relativity and Quantum Cosmology · Physics 2024-01-09 Tomohiro Harada , Takahisa Igata , Hiromi Saida , Yohsuke Takamori

Cumulative observational evidence confirm that the surface gravity of dark matter (DM) halo mu_{0 D} = r_0 rho_0 where r_0 and rho_0 are the halo core radius and central density, respectively, is nearly constant and independent of galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-15 H. J. de Vega , N. G. Sanchez

We investigate changes in Earth's atmospheric models coming from the $f(R,T)$ modified theory of gravity, in which the gravitational Lagrangian is given by an arbitrary function of the Ricci scalar and the trace of the stress-energy tensor.…

General Relativity and Quantum Cosmology · Physics 2019-05-29 Taylor M. Ordines , Eric D. Carlson

Recent experiments on two-dimensional (2D) electron systems have found a sharp increase in the effective mass of electrons with decreasing electron density. In an effort to understand this behavior we employ the many-body theory to…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 R. Asgari , B. Davoudi , B. Tanatar

We define passive gravitational mass operator of a hydrogen atom in the post-Newtonian approximation of general relativity and show that it does not commute with energy operator, taken in the absence of gravitational field. Nevertheless,…

General Relativity and Quantum Cosmology · Physics 2013-11-13 Andrei G. Lebed

The recently discovered apparent dramatic expansion in the effective radii of massive elliptical galaxies from $z \simeq 2$ to $z \simeq 0.1$ has been interpreted in terms of either galaxy mergers or the rapid loss of cold gas due to AGN…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 A. Mangalam , Gopal-Krishna , Paul J. Wiita

We develop an analytical model for the accretion and gravitational drag on a point mass that moves hypersonically in the midplane of a gaseous disk with a Gaussian vertical density stratification. Such a model is of interest for studying…

Astrophysics of Galaxies · Physics 2015-06-12 J. Cantó , A. Esquivel. F. J. Sánchez-Salcedo , A. C. Raga

Moller's tetrad gravitational energy-momentum "tensor" is evaluated for a small vacuum region using an orthonormal frame adapted to Riemann normal coordinates. We find that it does satisfy the highly desired property of being a positive…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Lau Loi So , James M. Nester

The gravitational redshift forms the central part of the majority of the classical tests for the general theory of relativity. It could be successfully checked even in laboratory experiments on the earth's surface. The standard derivation…

General Relativity and Quantum Cosmology · Physics 2015-05-28 L. Acedo , M. M. Tung

In a very interesting paper, Andr\'easson has recently proved that the gravitational mass of a spherically symmetric compact object of radius $R$ and electric charge $Q$ is bounded from above by the relation…

General Relativity and Quantum Cosmology · Physics 2019-04-03 Shahar Hod

The self-gravitational correction to a localized spherically-symmetric static energy distribution is obtained from energetically self-consistent upgraded Newtonian gravitational theory. The result is a gravitational redshift factor that is…

General Physics · Physics 2014-01-28 Steven Kenneth Kauffmann

In the standard cosmological model, the Universe consists mainly of two invisible substances: vacuum energy with constant mass-density rho_v=\Lambda/(8pi G) (where Lambda is a `cosmological constant' originally proposed by Einstein and G is…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Matthew G. Walker , Abraham Loeb

The turbulence driven by gravitational instabilities (GIs) can amplify magnetic fields in massive gaseous disks. This GI dynamo may appear in young circumstellar disks, whose weak ionization challenges other amplification routes, as well as…

Solar and Stellar Astrophysics · Physics 2022-07-27 William Béthune , Henrik Latter

In this paper the basic model for the anisotropic geometrodynamics (AGD) is introduced and used to discuss the classical GRT tests - orbit precession, light bending and gravitational red shift - on the galactic scale. It is shown that the…

General Physics · Physics 2009-10-20 Sergey Siparov

In this work, we present a review of Energy-Momentum Squared Gravity (EMSG) -- more specifically, $f(R,T_{\mu\nu}T^{\mu\nu})$ gravity, where $R$ represents the Ricci scalar and $T_{\mu\nu}$ denotes the energy-momentum tensor. The inclusion…

General Relativity and Quantum Cosmology · Physics 2024-08-27 Ricardo A. C. Cipriano , Nailya Ganiyeva , Tiberiu Harko , Francisco S. N. Lobo , Miguel A. S. Pinto , João Luís Rosa

We define gravitational mass operator of a hydrogen atom in the post-Newtonian approximation of the General Relativity and show that it does not commute with energy operator. Nevertheless, the equivalence between the expectation values of…

General Relativity and Quantum Cosmology · Physics 2011-11-24 A. G. Lebed

We address the question whether a medium featuring $p + \rho = 0$, dubbed $\Lambda$- medium, has to be necessarily a cosmological constant. By using effective field theory, we show that this is not the case for a class of media comprising…

General Relativity and Quantum Cosmology · Physics 2019-04-16 Marco Celoria , Denis Comelli , Luigi Pilo

The energy-momentum for a gravitating system can be considered by the tetard teleparalle gauge current in orthonormal frames. Whereas the Einstein pseudotensor used holonomic frames. Tetrad expression itself gives a better result for…

General Relativity and Quantum Cosmology · Physics 2009-11-13 Lau Loi So

A simple generalization to Einstein's general relativity (GR) was recently proposed which allows a correction term $T_{\alpha\beta}T^{\alpha\beta}$ in the action functional of the theory. This theory is called Energy-Momentum Squared…

General Relativity and Quantum Cosmology · Physics 2018-07-25 Nasrin Nari , Mahmood Roshan

We numerically calculate equilibrium configurations of uniformly rotating and charged neutron stars, in the case of insulating material and neglecting the electromagnetic forces acting on the equilibrium of the fluid. This allows us to…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Jerome Novak , Emmanuel Marcq