Related papers: Gravitational antiscreening in stellar interiors
We investigate realistic models of compact objects, focusing on neutron and strange stars, composed by dense matter and dark energy in the form of a simple fluid or scalar field interacting with matter. For the dark energy component, we use…
We study the weak-field limit of string-dilaton gravity and derive corrections to the Newtonian potential which strength directly depends on the self interaction potential and the nonminimal coupling of the dilaton scalar field. We discuss…
With regard to the coupling constant and the strong magnetic field of neutron stars, we have studied these stars in the 4D Einstein Gauss Bonnet (4D EGB) gravity model in order to grasp a better understanding of these objects. In this…
General properties of neutron stars are briefly reviewed with an emphasis on the indispensability of general relativity in our understanding of these fascinating objects. In Newtonian gravity the pressure within a star merely plays the role…
It is argued that the surface radius of a compact source can not be less than its gravitational radius due to the strong gravitational time dilation effects. The such "topological" difference between the Newtonian and relativistic gravity…
Graviton pairing and destruction of these pairs under collisions with bodies may lead to the Newtonian attraction. It opens us a new way to a very-low-energy quantum gravity model. In the model by the author, cosmological redshifts are…
Theories beyond the standard model include a number of new particles some of which might be light and weakly coupled to ordinary matter. Such particles affect equation of state of nuclear matter and can shift admissible masses of neutron…
We investigate the effects of strong magnetic fields upon the gross properties of neutron and protoneutron stars. In our calculations, the neutron star matter was approximated by the pure neutron matter. Using the lowest order constrained…
Astrophysical and cosmological arguments and observations give us the most restrictive constraints on neutrino masses, electromagnetic couplings, and other properties. Conversely, massive neutrinos would contribute to the cosmic dark-matter…
Using a perturbative approach we solve stellar structure equations for low-density (solar-type) stars whose interior is described with a polytropic equation of state in scenarios involving a subset of modified gravity theories. Rather than…
Surface tension (S) is due to the inward force experienced by particles at the surface and usually gravitation does not play an important role in this force. But in compact stars the gravitational force on the particles is very large and S…
We study slowly-rotating neutron stars in ghost-free massive bigravity. This theory modifies General Relativity by introducing a second, auxiliary but dynamical tensor field that couples to matter through the physical metric tensor through…
We investigate theoretical and observational constraints on the mass-radius relations for neutron stars. For that purpose we consider the model of neutron stars taking into considerations strong, weak, electromagnetic and gravitational…
We present the first numerical solutions of the coupled Einstein-Maxwell equations describing rapidly rotating neutron stars endowed with a magnetic field. These solutions are fully relativistic and self-consistent, all the effects of the…
We study relativistic stars in the scale-dependent scenario, which is one of the approaches to quantum gravity, and where Newton's constant is promoted to a scale-dependent quantity. First, the generalized structure equations are derived…
In this paper a quantum-mechanical behaviour of neutrons in gravitational fields is considered. A first estimation is made using the semiclassical approximation, neglecting General Relativity, magnetic and rotation effects, for neutrons in…
Recently, gravitational microlensing has been investigated in the framework of the weak field limit of fourth order gravity theory. However, solar system data (i.e. planetary periods and light bending) can be used to put strong constraints…
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…
Einstein-Cartan gravity is a close historical sibling of general relativity that allows for spacetime torsion. As a result, angular momentum couples to spacetime geometry in a similar way to energy. While consequences of this are well…
Modifications to Newtonian dynamics at low accelerations have long been proposed as an alternative to dark matter to explain galaxy rotation curves. More recently, similar corrections have been invoked to interpret anomalies in…