Slowly rotating neutron and strange stars inR²gravity

Abstract

In the present paper we investigate self-consistently slowly rotating neutron and strange stars in Rsquared gravity. For this purpose we first derive the equations describing the structure of the slowly rotating compact stars in f (R)-gravity and then simultaneously solve the exterior and the interior problem. The structure of the slowly rotating neutron stars is studied for two different hadronic equations of state and a strange matter equation of state. The moment of inertia and its dependence on the stellar mass and the R-squared gravity parameter a is also examined in details. We find that the neutron star moment of inertia for large values of the parameter a can be up to 30% larger compared to the corresponding general relativistic models. This is much higher than the change in the maximum mass induced by R-squared gravity and is beyond the EOS uncertainty. In this way the future observations of the moment of inertia of compact stars could allow us to distinguish between general relativity and f (R) gravity, and more generally to test the strong field regime of gravity.

Accretion disks around neutron and strange stars inR+aR2gravity

“…This is the so-called R 2 gravity. The equations describing slowly rotating stable stationary neutron star models as well as rapidly rotating ones in R 2 gravity can be found in [28][29][30]. The numerical computations are made with modification [30,31] of the RNS code [32].…”

“…There are two reasons to do this. First, the deviations from the GR case are close to the maximal for this value [28][29][30], hence it is a good starting point for investigation. The second reason is the relation between the parameter a and the range around the star in which the effect of the R 2 gravity is most pronounced.…”

Physical attributes of anisotropic compact stars in f(R, G) gravity

“…Many EOS parameters have been considered in the literature in different cosmological contexts. Staykov et al [42] used two different hadronic parameters and a strange matter EOS parameter to study the structure of rotating neutron stars. Quadratic EOS parameters have been used to study the properties of compact stars [46,47].…”

“…Different properties like mass, radius and moment of inertia of neutron stars are studied and a comparison has been developed with GR and alternative theories of gravity [41]. Some investigations of the structure of slowly rotating neutron stars in R 2 gravity have been done using two different hadronic parameters and a strange matter equation of state (EOS) parameter [42]. The mass ratio for compact objects in the presence of a cosmological constant has been derived [43].…”

Emerging anisotropic compact stars in $$f(\mathcal {G},T)$$ f ( G , T ) gravity

“…Various physical properties, such as mass, radius, and moment of inertia, of neutron stars have been investigated and a comprehensive comparison has been established with GR and modified theories of gravity [20]. Some interesting investigations related to the structure of slowly rotating neutron stars in R 2 gravity have been accomplished by making use of two distinct hadronic and a strange matter EOS parameters [21]. For a comprehensive study, some fascinating results can be found in [22][23][24][25][26][27][28].…”