English
Related papers

Related papers: NewtonPlus: Approximating Relativistic Effects in …

200 papers

General relativistic calculations are made of neutrino-antineutrino annihilation into electron-positron pairs near the surface of a neutron star. It is found that the efficiency of this process is enhanced over the Newtonian values up to a…

Astrophysics · Physics 2009-10-31 Jay D. Salmonson , James R. Wilson

The basic equations describing a Newtonian universe with uniform pressure are reexamined. We argue that in the semi-classical formulation adopted in the literature the continuity equation has a misleading pressure gradient term. When this…

Astrophysics · Physics 2016-01-13 J. A. S. Lima , V. Zanchin , R. Brandenberger

We extend the systematic calculation of an approximately relativistic Hamiltonian for centre of mass and internal dynamics of an electromagnetically bound two-particle system by Sonnleitner and Barnett [1] to the case including a weak…

Quantum Physics · Physics 2019-11-27 Philip K. Schwartz , Domenico Giulini

Quasi-universal relations are known to exist among various neutron star observables that do not depend sensitively on the underlying nuclear matter equations of state. For example, some of these relations imply that the tidally induced…

General Relativity and Quantum Cosmology · Physics 2025-07-15 Takuya Katagiri , Gowtham Rishi Mukkamala , Kent Yagi

A new class of relativistic stellar structure equations which include the effects of an energy-dependent Newton coupling is presented. Significant modifications in the mass-radius relation for neutron stars are possible only if the running…

General Relativity and Quantum Cosmology · Physics 2020-01-16 Alfio Bonanno , Roberto Casadio , Alessia Platania

Gravitational waves are being shown to derive directly from Newtonian dynamics for a continuous mass distribution, e g compressible fluids or equivalent. It is shown that the equations governing a continuous mass distribution, i e the…

General Physics · Physics 2024-05-20 Peter Vadasz

We present the first numerical relativity simulations of the gravitational scattering of two neutron stars. Constraint-satisfying initial data for two equal-mass nonspinning sequences are constructed at fixed energy and various initial…

General Relativity and Quantum Cosmology · Physics 2025-12-03 Joan Fontbuté , Sebastiano Bernuzzi , Piero Rettegno , Simone Albanesi , Wolfgang Tichy

A Newtonian approach to quantum gravity is studied. At least for weak gravitational fields it should be a valid approximation. Such an approach could be used to point out problems and prospects inherent in a more exact theory of quantum…

General Relativity and Quantum Cosmology · Physics 2011-04-07 Johan Hansson

The general relativistic treatment of gravitation can be extended by preserving the geometrical nature of the theory but modifying the form of the coupling between curvature and stress tensors. The gravitation constant is thus replaced by…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Marc-Thierry Jaekel , Serge Reynaud

We discuss the underlying relativistic physics which causes neutron stars to compress and collapse in close binary systems as has recently been observed in numerical (3+1) dimensional general relativistic hydrodynamic simulations. We show…

General Relativity and Quantum Cosmology · Physics 2016-08-25 G. J. Mathews , P. Marronetti , J. R. Wilson

We develop a description of tidal effects in astrophysical systems using effective field theory techniques. While our approach is equally capable of describing objects in the Newtonian regime (e.g. moons, rocky planets, main sequence stars,…

General Relativity and Quantum Cosmology · Physics 2016-03-29 Solomon Endlich , Riccardo Penco

We consider an extension of the recent experiment with ultracold neutrons and the quantization of its vertical motion in order to test the Weak Equivalence Principle. We show that an improvement on the energy resolution of the experiment…

High Energy Physics - Phenomenology · Physics 2017-08-23 O. Bertolami , F. M. Nunes

Employing a simplified version of the Israel-Stewart formalism for general-relativistic shear-viscous hydrodynamics, we perform axisymmetric general-relativistic simulations for a rotating neutron star surrounded by a massive torus, which…

High Energy Astrophysical Phenomena · Physics 2017-04-26 Masaru Shibata , Kenta Kiuchi , Yu-ichiro Sekiguchi

This work expands previous efforts, within the classical theories of Special and General Relativity, to include tachyons (faster-than-light particles) along with ordinary (slower-than-light) particles at any energy. The objective here is to…

General Relativity and Quantum Cosmology · Physics 2019-07-24 Charles Schwartz

The gravitational analogue of the electromagnetic Meissner effect is investigated. Starting from the post-Newtonian approximation to general relativity we arrive at gravitational London equations, predicting a gravitational Meissner effect.…

High Energy Physics - Theory · Physics 2007-05-23 R. P. Lano

Supernovae are one of the most promising gravitational wave sources. But, since the system of the supernovae is nearly spherically symmetric, the expected gravitational waves from them are relatively weak, compared to the case of the…

General Relativity and Quantum Cosmology · Physics 2026-04-22 Hajime Sotani

Two questions that naturally arise in N-body simulations of stellar systems are: (1) How can we compare experiments that employ different types of softened gravity? (2) Given a particular type of softened gravity, which choices of the…

Astrophysics · Physics 2007-05-23 Alessandro B. Romeo

Using the numerical simulation data for two-dimensional core-collapse supernova, we examine the protoneutron star (PNS) asteroseismology with the relativistic Cowling approximation. As shown in the previous study, the gravitational wave…

High Energy Astrophysical Phenomena · Physics 2021-12-15 Hajime Sotani , Tomoya Takiwaki , Hajime Togashi

Neutron stars that are cold enough should have two or more superfluids/supercondutors in their inner crusts and cores. The implication of superfluidity/superconductivity for equilibrium and dynamical neutron star states is that each…

General Relativity and Quantum Cosmology · Physics 2009-11-10 G. L. Comer

Core collapse supernovae are a promising source of detectable gravitational waves. Most of the existing (multidimensional) numerical simulations of core collapse in general relativity have been done using approximations of the Einstein…

Astrophysics · Physics 2009-11-10 P. Cerda-Duran , G. Faye , H. Dimmelmeier , J. A. Font , J. M. Ibanez , E. Mueller , G. Schaefer