arXiv subjects

Hari K. Kunduri

Publications and source records attributed to Hari K. Kunduri.

56 records · Page 4Linked to original sources

arXiv2004

Gravitational wave solutions in string and M-theory AdS Backgrounds

In this paper, we present several gravitational wave solutions in AdS_5 X S^5 string backgrounds, as well as in AdS_7 X S^4 and AdS_4 X S^7 backgrounds in M-theory, generalizing the results of hep-th/0403253 by one of the authors. In each case, we present the general form of such solutions and give explicit examples, preserving certain amount of supersymmetry, by taking limits on known BPS D3 and M2, M5-brane solutions in pp-wave backgrounds. A key feature of our examples is the possibility of a wider variety of wave profiles, than in pure gravity and string/M-theory examples known earlier, coming from the presence of various p-form field strengths appearing in the gravitational wave structure.

hep-th↗

arXiv2003

Homogeneous Plane-wave Spacetimes and their Stability

We consider the stability of spatially homogeneous plane-wave spacetimes. We carry out a full analysis for plane-wave spacetimes in (4+1) dimensions, and find there are two cases to consider; what we call non-exceptional and exceptional. In the non-exceptional case the plane waves are stable to (spatially homogeneous) vacuum perturbations as well as a restricted set of matter perturbations. In the exceptional case we always find an instability. Also we consider the Milne universe in arbitrary dimensions and find it is also stable provided the strong energy condition is satisfied. This implies that there exists an open set of stable plane-wave solutions in arbitrary dimensions.

gr-qc↗