相关论文: Dark stars in Starobinsky's model
Axions and axion-like particles are a leading model for the dark matter in the Universe; therefore, dark matter halos may be boson stars in the process of collapsing. We examine a class of static boson stars with a non-minimal coupling to…
We investigate various anisotropic spherical distributions of charged celestial bodies within the context of f(R) gravity, where R represents the Ricci scalar. The properties of specific charged compact objects are analyzed by using the…
We study an impact of asymmetric fermionic dark matter on neutron star properties, including tidal deformability, mass, radius, etc. We present the conditions at which dark matter particles tend to form a compact structure in a core of the…
We study the Starobinsky or $R^2$ model of $f(R)=R+\alpha R^2$ for neutron stars with the structure equations represented by the coupled differential equations and the \emph{polytropic} type of the matter equation of state. The junction…
The latest observations from the LIGO-Virgo indicated the existence of mass-gap region astrophysical objects. This is a rather sensational observation and there are two possibilities for the nature of these mass-gap region astrophysical…
Non-rotating neutron stars are generally treated in theoretical studies as perfect spheres. Such a treatment, however, may not be correct if strong magnetic fields are present (such as for magnetars) and/or the pressure of the matter in the…
In this paper, we study the $F(R, G)$ gravity model with an interacting model by flat-FRW metric in a viscous fluid. We consider that the universe dominates with components of dark matter and dark energy. This means that the dark matter…
We develop the general scheme for modified $f(R)$ gravity reconstruction from any realistic FRW cosmology. We formulate several versions of modified gravity compatible with Solar System tests where the following sequence of cosmological…
A massive star undergoes a continual gravitational collapse when the pressures inside the collapsing star become insufficient to balance the pull of gravity. The Physics of gravitational collapse of stars is well studied. Using general…
We study the strong gravity regime in viable models of so-called f(R) gravity that account for the observed cosmic acceleration. In contrast with recent works suggesting that very relativistic stars might not exist in these models, we find…
Boson stars, self-gravitating objects made of a complex scalar field, have been proposed as simple models for very different scenarios, ranging from galaxy dark matter to black hole mimickers. Here we focus on a very compact type of boson…
Boson stars coupled to Einstein's general relativity possess some features similar to gravastars, such as the anisotropy in principal pressures and relatively large compactness ($\mu_{max} = 0.32$). However, no matter how large the…
Massive boson stars are self-gravitating configurations of self-interacting scalar fields and can be modeled by a massive scalar field with a quartic self-interaction potential. It has been shown that the equation of state and static…
We review modified $F(R)$ gravity as realistic candidate to describe the observable universe expansion history. We show that recent cosmic acceleration, radiation/matter-dominated epoch and inflation could be realized in the framework of…
A model of compact object coupled to inhomogeneous anisotropic dark energy is studied. It is assumed a variable dark energy that suffers a phase transition at a critical density. The anisotropic Lambda-Tolman-Oppenheimer-Volkoff equations…
Neutron stars could contain a mixture of ordinary nuclear matter and dark matter, such that dark matter could influence observable properties of the star, such as its mass and radius. We study these dark matter admixed neutron stars for two…
Viable corrections to the matter sector of Poisson's equation may result in qualitatively different astrophysical phenomenology, for example the gravitational collapse and the properties of compact objects can change drastically. We discuss…
The mass of compact objects in General Relativity (GR), which as is well known, is obtained via the Tolman - Oppenheimer - Volkov (TOV) equations, is a well defined quantity. However, in alternative gravity, this is not in general the case.…
We investigate the cosmological implications of a new class of modified gravity, where the field equations generically include higher-order derivatives of the matter fields, arising from the introduction of non-dynamical auxiliary fields in…
The conventional Friedmann cosmology is known to be in tension with the existence of stable particles having interaction strength typical for supersymmetry and heavier than several TeV. A possible way to save life of such particles may be a…