Stable relativistic polytropic objects with cosmological constant

Non–Relativistic Spacetimes with Cosmological Constant

Recent data on supernovae favor high values of the cosmological constant. Spacetimes with a cosmological constant have non–relativistic kinematics quite different from Galilean kinematics. De Sitter spacetimes, vacuum solutions of Einstein’s equations with a cosmological constant, reduce in the non–relativistic limit to Newton–Hooke spacetimes, which are non–metric homogeneous spacetimes with n...

General Relativistic Static Fluid Solutions with Cosmological Constant

General Relativistic Stars : Polytropic Equations of State

In this paper, the gravitational field equations for static spherically symmetric perfect fluid models with a polytropic equation of state, p = kρ1+1/n, are recast into two complementary 3-dimensional regular systems of ordinary differential equations on compact state spaces. The systems are analyzed numerically and qualitatively, using the theory of dynamical systems. Certain key solutions are...

Relativistic Parker winds with variable effective polytropic index

Spherically symmetric hydrodynamical outflows accelerated thermally in the vicinity of a compact object are studied by generalizing an equation of state with a variable effective polytropic index, appropriate to describe relativistic temperatures close to the central object and nonrelativistic ones further away. Relativistic effects introduced by the Schwarzschild metric and the presence of rel...

Planetary Perturbation with cosmological Constant

A contribution of quantum vacuum to the energy momentum tensor is inevitably experienced in the present universe. One requires the presence of non-zero cosmological constant (Λ) to make the various observations consistent. A case of Λ in the Schwarzschild de Sitter space-time shows that precession of perihelion orbit provides a sensative solar test for non-zero Λ. Application of the relations i...