English
Related papers

Related papers: Neutron stars in generalized f(R) gravity

200 papers

Horndeski's theory of gravity is the most general scalar-tensor theory with a single scalar whose equations of motion contain at most second-order derivatives. A subsector of Horndeski's theory known as "Fab Four" gravity allows for…

General Relativity and Quantum Cosmology · Physics 2016-06-29 Andrea Maselli , Hector O. Silva , Masato Minamitsuji , Emanuele Berti

Low-mass neutron stars are directly associated with the nuclear saturation parameters because their central density is definitely low. We have already found a suitable combination of nuclear saturation parameters for expressing the neutron…

Nuclear Theory · Physics 2022-11-16 Hajime Sotani , Shinsuke Ota

We study isolated and binary neutron stars in dynamical Chern-Simons gravity. This theory modifies the Einstein-Hilbert action through the introduction of a dynamical scalar field coupled to the Pontryagin density. We here treat this theory…

General Relativity and Quantum Cosmology · Physics 2016-04-13 Kent Yagi , Leo C. Stein , Nicolas Yunes , Takahiro Tanaka

In this article we study the hydrostatic equilibrium configuration of neutron stars and strange stars, whose fluid pressure is computed from the equations of state $p=\omega\rho^{5/3}$ and $p=0.28(\rho-4{\cal B})$, respectively, with…

General Relativity and Quantum Cosmology · Physics 2016-07-12 P. H. R. S. Moraes , José D. V. Arbañil , M. Malheiro

In this work, we investigate neutron stars (NSs) in the strong field regime within the framework of symmetric teleparallel $f(Q)$ gravity, considering three representative models: linear, logarithmic, and exponential. While Bayesian studies…

General Relativity and Quantum Cosmology · Physics 2026-02-19 Sneha Pradhan , N. K. Patra , Kai Zhou , P. K. Sahoo

The equation of state of beta-stable and charge neutral nucleonic matter is computed within the SU(2) parity doublet model in mean field and in the relativistic Hartree approximation. The mass of the chiral partner of the nucleon is assumed…

Nuclear Theory · Physics 2008-11-26 V. Dexheimer , G. Pagliara , L. Tolos , J. Schaffner-Bielich , S. Schramm

Aether Scalar-Tensor theory is a modification of general relativity proposed to explain galactic and cosmological mass discrepancies conventionally attributed to dark matter.~The theory is able to fit the cosmic microwave background and the…

General Relativity and Quantum Cosmology · Physics 2025-02-20 Christopher Reyes , Jeremy Sakstein

We formulate the generalized Tolman-Oppenheimer-Volkoff equations for the $f(\hat{R})$ Palatini gravity in the case of static and spherical symmetric geometry. We also show that a neutron star is a stable system independently of the form of…

General Relativity and Quantum Cosmology · Physics 2018-05-31 Aneta Wojnar

The parity doublet model, containing the SU(2) multiplets including the baryons identified as the chiral partners of the nucleons is applied to neutron stars. The maximum mass for the star is calculated for different stages of the cooling…

Astrophysics · Physics 2008-01-17 V. Dexheimer , S. Schramm , H. Stoecker

The so-called hyperon puzzle in the theory of neutron stars is considered in the framework of modified $f(R)$ gravity. We show that for simple hyperon equations of state, it is possible to obtain the maximal neutron star mass which…

General Relativity and Quantum Cosmology · Physics 2015-06-18 Artyom V. Astashenok , Salvatore Capozziello , Sergei D. Odintsov

We present a numerical scheme that solves the initial value problem in full general relativity for a binary neutron star in quasi-equilibrium. While Newtonian gravity allows for a strict equilibrium, a relativistic binary system emits…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Thomas W. Baumgarte , Stuart L. Shapiro , Gregory B. Cook , Mark A. Scheel , Saul A. Teukolsky

We compute families of spherically symmetric neutron-star models in two-derivative scalar-tensor theories of gravity with a massive scalar field. The numerical approach we present allows us to compute the resulting spacetimes out to…

General Relativity and Quantum Cosmology · Physics 2021-05-21 Roxana Rosca-Mead , Christopher J. Moore , Ulrich Sperhake , Michalis Agathos , Davide Gerosa

We explore gravity-independent equations of state for neutron stars, particularly focusing on twin stars. Examining four categories, we emphasize their behavior in both General Relativity and Palatini gravity. Additionally, we discuss a…

General Relativity and Quantum Cosmology · Physics 2024-02-07 Eva Lope-Oter , Aneta Wojnar

We investigate in this paper the structures of neutron stars under the strong magnetic field in the framework of $f(T)$ gravity where $T$ denotes the scalar torsion. The TOV equations in this theory of gravity have been considered and…

General Physics · Physics 2017-09-28 M. G. Ganiou , C. Aïnamon , M. J. S. Houndjo , J. Tossa

Neutron stars are some of the densest manifestations of massive objects in the universe. They are ideal astrophysical laboratories for testing theories of dense matter physics and provide connections among nuclear physics, particle physics…

Astrophysics · Physics 2011-05-05 J. M. Lattimer , M. Prakash

We derive the equation for pressure within a neutron star, taking into account a non-zero cosmological constant ($\Lambda$). We then examine the stability of the neutron star's equilibrium state in the presence of cosmological constant. Our…

General Relativity and Quantum Cosmology · Physics 2025-04-22 Naveen K. Singh , Gopal Kashyap

Neutron stars are one of the most extreme objects in the universe, with densities that can exceed those of atomic nuclei and gravitational fields that are among the strongest known. Theoretical and observational research on neutron stars…

High Energy Astrophysical Phenomena · Physics 2023-03-16 J. Alfredo Collazos

In the present paper the axial quasi-normal modes of neutron stars in $f(R)$ gravity are examined using a large set of equations of state. The numerical calculations are made using two different approaches -- performing time evolution of…

General Relativity and Quantum Cosmology · Physics 2018-12-05 Jose Luis Blázquez-Salcedo , Daniela D. Doneva , Jutta Kunz , Kalin V. Staykov , Stoytcho S. Yazadjiev

Stars are essentially gravitationally stabilised thermonuclear reactors in hydrostatic equilibrium. The fundamental differential equation for all Newtonian gaseous stars in equilibrium is \begin{align}…

General Relativity and Quantum Cosmology · Physics 2021-09-07 Steven D Miller

In the last few decades, lots of universal relations between different global physical quantities of neutron stars have been proposed to constrain the unobservable or hard to be observed properties of neutron stars. But few of them are…

General Relativity and Quantum Cosmology · Physics 2020-08-10 Wenjie Sun , Dehua Wen , Jue Wang