30 research outputs found
Raychaudhuri Equation in an Anisotropic Universe with Anisotropic Sources
In this paper we investigate the fate of the universe with an anisotropic
background sourced by anisotropic matter. We see the behaviour of the
Raychaudhuri Equation and investigate wheather a congrurence of time like
geodesics focus to a point in a universe with Bianchi I background which is
dictated by anisotropic sources like cosmic strings, domain walls, magnetic
field and lorentz violating magnetic field each separately. Thus, Focussing
theorem has been checked both for initially contracting and diverging universe
with each of these anisotropic sources.Comment: 6 pages, 10 figure
Quantum geometric formulation of Brans-Dicke theory for Bianchi I spacetime
We consider a formulation of the Brans-Dicke theory in Jordan's frame for
Bianchi-I spacetime within the framework of loop quantum gravity. The
robustness of singularity resolutions due to the quantum effects is explicitly
verified. We also present an exploration of the effects of quantum geometry on
the background dynamics. In particular, starting with a detailed constraint
analysis, we present the off-shell Lie algebra of the full theory in the
geometrodynamic phase space. This is followed by casting the theory in terms of
the Yang-Mills phase space variables suitable for invoking loop quantization
and show that the system is highly nonlinear. Finally, we present the
quantum-corrected effective dynamics that resolve the initial singularityComment: 1