Related papers: Stellar structure model in hydrostatic equilibrium…
We derive the equilibrium hydrostatic equation of a spherical star for any gravitational Lagrangian density of the form $L=\sqrt{-g}f(R)$. The Palatini variational principle for the Helmholtz Lagrangian in the Einstein gauge is used to…
In Palatini $f(R)$ gravity, the parameters of the Schwarzschild - de Sitter solution as well as the whole interior solutions of compact objects are expected to change when compared to general relativity. We solve the Palatini field…
We consider static spherically symmetric self-gravitating configurations of the perfect fluid within the framework of the torsion-based extended theory of gravity. In particular, we use the covariant formulation of $f(T)$ gravity with $f(T)…
We consider the internal structure and the physical properties of specific classes of neutron, quark and Bose-Einstein Condensate stars in the hybrid metric-Palatini gravity theory, which is a combination of the metric and Palatini $f(R)$…
In this special issue article, I review some of the accomplishments of the chiral mean field (CMF) model, which contains nucleon, hyperon, and quark degrees of freedom, and its applications to proto-neutron and neutron stars. I also present…
We calculate static and spherically symmetric solutions for the Rastall modification of gravity to describe Neutron Stars (NS). The key feature of the Rastall gravity is the non-conservation of the energy-momentum tensor proportionally to…
Background: Theoretical approaches based on density functional theory provide the only tractable method to incorporate the wide range of densities and isospin asymmetries required to describe finite nuclei, infinite nuclear matter, and…
In this last decade, our knowledge of evolutionary and structural properties of stars of different mass and chemical composition has significantly improved. This notwithstanding, updated stellar models are still affected by significant and,…
We perform simulations of relativistic binary stars in post-Newtonian gravity to investigate their dynamical stability prior to merger against gravitational collapse in a tidal field. In general, our equations are only strictly accurate to…
We discuss the Mass -Radius diagram for static neutron star models obtained by the numerical solution of modified Tolman-Oppenheimer-Volkoff equations in $f(R)$ gravity where the Lagrangians $f(R)=R+\alpha R^2 (1+\gamma R)$ and…
Recently, we have shown that dynamically stable ergostar solutions (equilibrium neutron stars that contain an ergoregion) with a compressible and causal equation of state exist [A. Tsokaros, M. Ruiz, L. Sun, S. L. Shapiro, and K. Ury\=u,…
This paper studies the structural formation of various spherically symmetric anisotropic configured stars in $f(\mathcal{R},\mathcal{T},\mathcal{Q})$ gravity under the influence of electromagnetic field, where…
A numerical method of mode analysis of rapidly rotating relativistic stellar models by the Cowling approximation is applied to rotating neutron stars with realistic equations of state. For selected equations of state, eigenvalues and…
The main aim of this study is to examine the behaviour of physical parameters of an anisotropic compact star model demonstrating spherical symmetry in F(Q) modified gravity. To evaluate the behaviour and the stability of an anisotropic…
In the present paper, we have investigated the Friedmann Robertson Walker (FRW) model in viable $f(R,T)$ gravity with $f(R,T)$ function proposed as $f(R,T)=R +\xi T^{1/2}$, where $\xi$ is an arbitrary constant, $R$ is the scalar curvature…
Nuclear matter and neutron stars are studied in the framework of an extended relativistic mean-field (RMF) model with higher-order derivative and density dependent couplings of nucleons to the meson fields. The derivative couplings lead to…
Gravitational wave and electromagnetic observations can provide new insights into the nature of matter at supra-nuclear densities inside neutron stars. Improvements in electromagnetic and gravitational wave sensing instruments continue to…
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…
We revisit the analysis made by Hwang and Noh [JCAP 1310 (2013)] aiming the construction of a Newtonian set of equations incorporating pressure effects typical of the General Relativity theory. We explicitly derive the Hwang-Noh equations,…
The Noether Symmetry Approach can be used to construct spherically symmetric solutions in $f({\cal R})$ gravity. Specifically, the Noether conserved quantity is related to the gravitational mass and a gravitational radius that reduces to…