Neutron stars in general relativity and scalar-tensor theory of gravity

f(R) gravity and scalar-tensor theory

In the present paper we will investigate the relation between scalar-tensor theory and f(R) theories of gravity. Such studies have been performed in the past for the metric formalism of f(R) gravity; here we will consider mainly the Palatini formalism, where the metric and the connections are treated as independent quantities. We will try to investigate under which circumstances f(R) theories o...

Strange quark matter attached to string cloud in general scalar tensor theory of gravitation

Bianchi type-VI0 space time with strange quark matter attached to string cloud in Nordtvedt [1] general scalar tensor theory of gravitation with the help of a special case proposed by Schwinger [2] is obtained. The field equations have been solved by using the anisotropy feature of the universe in the Bianchi type-VI0 space time. Some important features of the model, thus obtained, have been di...

Collapse of magnetized hypermassive neutron stars in general relativity.

Hypermassive neutron stars (HMNSs)--equilibrium configurations supported against collapse by rapid differential rotation--are possible transient remnants of binary neutron-star mergers. Using newly developed codes for magnetohydrodynamic simulations in dynamical spacetimes, we are able to track the evolution of a magnetized HMNS in full general relativity for the first time. We find that secula...

General Relativity and Compact Objects – Neutron Stars and Black Holes

Irrotational Binary Neutron Stars in Quasiequilibrium in General Relativity

Neutron stars in binary orbit emit gravitational waves and spiral slowly together. During this inspiral, they are expected to have very little vorticity. It is in fact a good approximation to treat the system as having zero vorticity, i.e., as irrotational. Because the orbital period is much shorter than the radiation reaction time scale, it is also an excellent approximation to treat the syste...