English
Related papers

Related papers: Stellar structure models in modified theories of g…

200 papers

The field equations of a generalized $f(R)$ type gravity model, in which there is an arbitrary coupling between matter and geometry, are obtained. The equations of motion for test particles are derived from a variational principle in the…

General Relativity and Quantum Cosmology · Physics 2009-05-26 T. Harko

Recently, several interesting proposals were made modifying the law of gravity on large scales, within a sensible relativistic formulation. This allows a precise formulation of the idea that such a modification might account for galaxy…

High Energy Physics - Phenomenology · Physics 2010-04-06 A. Aguirre , C. P. Burgess , A. Friedland , D. Nolte

Neutron stars are the densest known objects in the universe and an ideal laboratory for the strange physics of super-condensed matter. Theoretical studies in connection with recent observational data of isolated neutron stars, as well as…

Nuclear Theory · Physics 2021-11-09 P. S. Koliogiannis , A. Kanakis-Pegios , Ch. C. Moustakidis

The recent observations of neutron star mergers have changed our perspective on scalar- tensor theories of gravity, favouring models where gravitational waves travel at the speed of light. In this work we consider a scalar-tensor set-up…

General Relativity and Quantum Cosmology · Physics 2018-08-15 Javier Chagoya , Gianmassimo Tasinato

We study the effects of strong magnetic fields on the neutron star structure. If the interior field of a star is on the same order of the surface field currently observed, the influences of the magnetic field on the star mass and radius are…

Astrophysics · Physics 2014-10-13 Guangjun Mao , Akira Iwamoto , Zhuxia Li

We find some exact solutions for constant-density and quark matter equations of state in stellar structure models framed within the $f(R,T)=R+\lambda \kappa^2 T$ theory of gravity, where $R$ is the curvature scalar, $T$ the trace of the…

General Relativity and Quantum Cosmology · Physics 2025-04-09 Aliya Batool , Abdul Malik Sultan , Gonzalo J. Olmo , Diego Rubiera-Garcia

The interiors of neutron stars reach densities and temperatures beyond the limits of terrestrial experiments, providing vital laboratories for probing nuclear physics. While the star's interior is not directly observable, its pressure and…

High Energy Astrophysical Phenomena · Physics 2024-02-13 Delaney Farrell , Pierre Baldi , Jordan Ott , Aishik Ghosh , Andrew W. Steiner , Atharva Kavitkar , Lee Lindblom , Daniel Whiteson , Fridolin Weber

Dark energy stars research is an issue of great interest since recent astronomical observations with respect to measurements in distant supernovas, cosmic microwave background and weak gravitational lensing confirm that the universe is…

General Relativity and Quantum Cosmology · Physics 2021-06-18 M. Malaver , H. D. Kasmaei , R. Iyer , S. Sadhukhan , A. Kar

Thanks to the space-based photometry missions CoRoT and Kepler, we now benefit from a wealth of seismic data for stars other than the sun. In the future, K2, Tess and Plato will provide further observations. The quality of this data may…

Solar and Stellar Astrophysics · Physics 2017-02-24 Gaël Buldgen , Daniel Reese , Marc-Antoine Dupret

In this work the influence of the post-Newtonian corrections to the equations of stellar structure is analysed. The post-Newtonian Lane-Emden equation follows from the corresponding momentum density balance equation. From a polytropic…

General Relativity and Quantum Cosmology · Physics 2022-11-21 Gilberto Medeiros Kremer

We study the structure of neutron stars in perturbative f(R) gravity models with realistic equations of state. We obtain mass-radius relations in a gravity model of the form f(R)=R+\alpha R^2. We find that deviations from the results of…

General Relativity and Quantum Cosmology · Physics 2015-05-18 A. Savas Arapoglu , Cemsinan Deliduman , K. Yavuz Eksi

A possible solution to the dark energy problem is that Einstein's theory of general relativity is modified. A suite of models have been proposed that, in general, are unable to predict the correct amount of large scale structure in the…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-28 Pedro G. Ferreira , Constantinos Skordis

Mass-varying massive gravity allows the graviton mass to vary according to different environments. We investigate neutron star and white dwarf solutions in this theory and find that the graviton mass can become very large near the compact…

General Relativity and Quantum Cosmology · Physics 2020-03-31 Xue Sun , Shuang-Yong Zhou

One of the key ingredients to understand the properties of neutrons stars is the equation of state at finite densities far beyond nuclear saturation. Investigating the phase structure of quark matter that might be realized in the core of NS…

Nuclear Theory · Physics 2010-03-04 T. Klahn , C. D. Roberts , D. B. Blaschke , F. Sandin

Differences in masses inferred from dynamics, such as velocity dispersions or X-rays, and those inferred from lensing are a generic prediction of modified gravity theories. Viable models however must include some non-linear mechanism to…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-25 Fabian Schmidt

The properties of dark matter admixed strange quark stars are investigated in the Starobinsky model of modified gravity. For quark matter we assume the MIT bag model, while self-interacting dark matter inside the star is modelled as a…

General Relativity and Quantum Cosmology · Physics 2018-02-14 Ilidio Lopes , Grigoris Panotopoulos

The present work is to introduce a new kind of modified gravitational theory, named as $f(\mathcal{R,G,T})$ (also $f(\mathcal{R,T,G})$) gravity, where $\mathcal{R}$ is the Ricci scalar, $\mathcal{G}$ is Gauss-Bonnet invariant and…

General Relativity and Quantum Cosmology · Physics 2021-11-16 M. Ilyas

In this lecture, we give a first introduction to neutron stars, based on fundamental physical principles. After outlining their outstanding macroscopic properties, as obtained from observations, we infer the extreme conditions of matter in…

High Energy Astrophysical Phenomena · Physics 2016-09-27 Pierre M. Pizzochero

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

The appearance of strangeness in the form of hyperons within the inner core of neutron stars is expected to affect its detectable properties such as its global structure or gravitational wave emission. In this work, we explore the parameter…

High Energy Astrophysical Phenomena · Physics 2023-12-19 Suprovo Ghosh , Bikram Keshari Pradhan , Debarati Chatterjee , Jürgen Schaffner-Bielich