38 research outputs found
Central Density Dependent Anisotropic Compact Stars
Stars can be treated as self-gravitating fluid. In this connection, we
propose a model for an anisotropic star under the relativistic framework of
Krori-Barua (1975) spacetime. It is shown that the solutions are regular and
singularity free. The uniqueness of the model is that interior physical
properties of the star solely depend on the central density of the matter
distribution
Lorentzian wormhole in the framework of loop quantum cosmology
In this paper, we construct a traversable static Lorentzian wormhole in the
effective scenario of Loop Quantum Cosmology (LQC), where the field equations
are modified due to the ultraviolet (UV) corrections introduced at large
space-time curvatures. A stable wormhole can be constructed in the effective
scenario without the violation of Null energy condition (NEC) by physical
matter at the throat. The NEC is effectively violated due to the corrections in
the field equations from LQC, resolving the Weyl curvature singularity at the
throat. However, the physical matter does violate the Strong energy condition
(SEC), suggesting the interesting possibility that dark energy can be harnessed
into a wormhole. A possible explanation for this is the presence of inherent
pressure isotropy in the UV-corrected field equations (discussed and compared
to braneworld wormholes in the discussion). No additional exotic ingredient
(violating NEC) is required, avoiding quantum instabilities. The tidal forces
at the throat do not diverge and also the throat is found to be stable. The
wormhole features an attractive geometry. LQC can resolve both types of
curvature singularities appearing at the black hole center and wormhole throat,
without exotic matter.Comment: 10 Pages, 4 Figure
Analytical model of strange star in the low-mass X-ray binary 4U 1820-30
In this article, we have proposed a model for a realistic strange star under
Tolman VII metric\citep{Tolman1939}. Here the field equations are reduced to a
system of three algebraic equations for anisotropic pressure. Mass, central
density and surface density of strange star in the low-mass X-ray binary 4U
1820-30 has been matched with the observational data according to our model.
Strange materials clearly satisfies the stability condition (i.e. sound
velocities < 1) and TOV-equation. Here also surface red shift of the star has
been found to be within reasonable limit.Comment: Some revisions have been made. Accepted in Eur.Phys.J.