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

200 papers

We have recently developed a neutron star model fulfilling global and not local charge neutrality, both in the static and in the uniformly rotating cases. The model is described by the coupled Einstein-Maxwell-Thomas- Fermi (EMTF)…

Solar and Stellar Astrophysics · Physics 2015-06-23 Riccardo Belvedere , Jorge Armando Rueda , Remo Ruffini

Motivated by the entropy-functional formulation of emergent gravity, in which spacetime is endowed with a thermodynamic entropy that, upon extremization, yields the Einstein field equations, we reformulate the onset of a neutron star as a…

General Relativity and Quantum Cosmology · Physics 2026-03-10 Wen-Xiang Chen

We study the structure of neutron stars in $f(R)=R+\alpha R^{2}$ theory of gravity (Starobinsky model), in an exact and non-perturbative approach. In this model, apart from the standard General Relativistic junction conditions, two extra…

General Relativity and Quantum Cosmology · Physics 2014-05-01 Apratim Ganguly , Radouane Gannouji , Rituparno Goswami , Subharthi Ray

Models of neutron stars (NSs) with hyperon cores are constructed with an effective chiral model in mean-field approximation. The hyperon couplings are fixed by reproducing their experimentally determined binding energies. The impact of…

Nuclear Theory · Physics 2019-01-31 Debashree Sen , Kinjal Banerjee , T. K. Jha

Heavy-neutrino (or neutralino) stars are studied using the general relativistic equations of hydrostatic equilibrium and the relativistic equation of state for degenerate fermionic matter. The Tolman-Oppenheimer-Volkoff equations are then…

Astrophysics · Physics 2009-10-30 Neven Bilic , Faustin Munyaneza , Raoul D. Viollier

For more than three decades, the inner crust of neutron stars, formed of a solid lattice of nuclear clusters coexisting with a gas of electrons and neutrons, has been traditionally studied in the Wigner-Seitz approximation. The validity of…

Astrophysics · Physics 2017-08-23 N. Chamel

In the light of the recent discovery of a neutron star with a mass accurately determined to be almost two solar masses, it has been suggested that hyperons cannot play a role in the equation of state of dense matter in $\beta$-equilibrium.…

Nuclear Theory · Physics 2022-10-26 D. L. Whittenbury , J. D. Carroll , A. W. Thomas , K. Tsushima , J. R. Stone

We investigate the challenges of constructing neutron star (NS) solutions in $f(\mathbb{Q})$ gravity, highlighting the importance of treating the affine connection as an active, dynamical component of the theory. We begin by clarifying…

General Relativity and Quantum Cosmology · Physics 2025-12-03 Lavinia Heisenberg , Carlos Pastor-Marcos

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…

General Relativity and Quantum Cosmology · Physics 2016-10-24 A. M. Oliveira , H. E. S. Velten , J. C. Fabris , L. Casarini

Since the derivation of a well-defined $D\to4$ limit for 4D Einstein-Gauss-Bonnet (4DEGB) gravity coupled to a scalar field, there has been considerable interest in testing it as an alternative to Einstein's general theory of relativity.…

General Relativity and Quantum Cosmology · Physics 2025-04-25 Alejandro Saavedra , Octavio Fierro , Michael Gammon , Robert B. Mann , Guillermo Rubilar

We construct sequences of rapidly rotating neutron stars in dilatonic Einstein-Gauss-Bonnet theory, employing two equations of state for the nuclear matter. We analyze the dependence of the physical properties of these neutron stars on the…

General Relativity and Quantum Cosmology · Physics 2016-06-22 Burkhard Kleihaus , Jutta Kunz , Sindy Mojica , Marco Zagermann

With the equations of state provided by the newly developed density dependent relativistic Hartree-Fock (DDRHF) theory for hadronic matter, the properties of the static and $\beta$-equilibrium neutron stars without hyperons are studied for…

Nuclear Theory · Physics 2010-11-23 Bao Yuan Sun , Wen Hui Long , Jie Meng , U. Lombardo

Nucleonic matter is described within a su(2) extended Nambu-Jona-Lasinio model. Several parametrizations with different nuclear matter saturation properties are proposed. At subsaturation, nuclear pasta phases are calculated within two…

Nuclear Theory · Physics 2016-07-27 Helena Pais , Débora P. Menezes , Constança Providência

The structure of neutron stars is considered from theoretical and observational perspectives. We demonstrate an important aspect of neutron star structure: the neutron star radius is primarily determined by the behavior of the pressure of…

Astrophysics · Physics 2008-11-26 J. M. Lattimer , M. Prakash

Although Lorentz symmetry is a staple of General Relativity (GR), there are several reasons to believe it may not hold in a more advanced theory of gravity, such as quantum gravity. Einstein-aether theory is a modified theory of gravity…

General Relativity and Quantum Cosmology · Physics 2023-06-22 Kai Vylet , Siddarth Ajith , Kent Yagi , Nicolás Yunes

We consider neutron star configurations in the scalar-tensor theory of gravity with the coupling between the kinetic term of a scalar field and the Einstein tensor (such the model is a subclass of Horndeski gravity). Neutron stars in this…

General Relativity and Quantum Cosmology · Physics 2023-01-18 Pavel E. Kashargin , Sergey V. Sushkov

It is assumed that, for weak spacetime curvature, the main gravitational effect of the quantum vacuum stress-energy corresponds to adding two terms to the Einstein-Hilbert action, proportional to the square of the curvature scalar and to…

General Relativity and Quantum Cosmology · Physics 2010-04-23 Emilio Santos

We calculate total masses and radii of neutron stars (NS) for pure neutron matter and nuclear matter in beta-equilibrium. We apply a relativistic nuclear matter equation of state (EOS) derived from Dirac-Brueckner-Hartree-Fock (DBHF)…

Nuclear Theory · Physics 2009-11-11 Plamen G. Krastev , Francesca Sammarruca

The question of whether quark matter exists in neutron stars is a long standing one. Generally one finds that a first order phase transition from baryons to quarks softens the equation of state so much that the star would collapse into a…

Nuclear Theory · Physics 2021-07-14 J. I. Kapusta , T. Welle

Although general relativistic cosmological solutions, even in the presence of pressure, can be mimicked by using neo-Newtonian hydrodynamics, it is not clear whether there exists the same Newtonian correspondence for spherical static…

General Relativity and Quantum Cosmology · Physics 2015-06-23 A. M. Oliveira , H. E. S. Velten , J. C. Fabris , I. G. Salako