5,827 research outputs found
Core-crust transition pressure for relativistic slowly rotating neutron stars
We study the influence of core-\textit{crust} transition pressure changes on
the general dynamical properties of neutron star configurations. First we study
the matching conditions in core-\textit{crust} transition pressure region,
where phase transitions in the equation of state causes energy density jumps.
Then using a surface \textit{crust} approximation, we can construct
configurations where the matter is described by the equation of state of the
core of the star and the core-\textit{crust} transition pressure. We will
consider neutron stars in the slow rotation limit, considering perturbation
theory up to second order in the angular velocity so that the deformation of
the star is also taken into account. The junction determines the parameters of
the star such as total mass, angular and quadrupolar momentum.Comment: 4 pages, 1 figur
New model of relativistic slowly rotating neutron stars with surface layer \textit{crust}: application to giant \textit{glitches} of Vela Pulsar
Introducing a surface layer of matter on the edge of a neutron star in slow
rigid rotation, we analyze, from an intrinsic point of view, the junction
conditions that must be satisfied between the interior and exterior solutions
of the Einstein equations. In our model the core-\textit{crust} transition
pressure arise as an essential parameter in the description of a configuration.
As an application of this formalism, we describe giant \textit{glitches} of the
Vela pulsar as a result of variations in the transition pressure, finding that
these small changes are compatible with the expected temperature variations of
the inner crust during \textit{glitch} time.Comment: 4 pages, 2 figures, to appear in Proceedings of Spanish Relativity
Meeting 2010 (ERE 2010) held in Granada, Spai
A wide family of singularity-free cosmological models
In this paper a family of non-singular cylindrical perfect fluid cosmologies
is derived. The equation of state corresponds to a stiff fluid. The family
depends on two independent functions under very simple conditions. A sufficient
condition for geodesic completeness is provided.Comment: 7 pages, RevTeX
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