Title : 
Degenerate extension of positive and negative mass Schwarzschild geometry 

Speaker  :  Sandipan Sengupta , IIT Kharagpur 
Date  :  April 22, 2019 
Time  :  3:30 PM 
Venue  :  Room 3307 
Abstract  : 
We define a smooth extension of the Schwarzschild exterior geometry, with the spe cial property that the curvature twoform field is finite everywhere. This spacetime is a solution to the first order field equations in vacuum by construction. Unlike the Kruskal Szekeres construction based on invertible metrics in the Einsteinian theory, it exhibits a vanishing metric determinant phase over an extended region. The invertible and non invertible phases of the tetrad meet at an intermediate hypersurface across which the components of the gaugecovariant fields are all continuous. These solutions could be particularly relevant in the study of singularities in general relativity as well as in the context of information loss problem. We also demonstrate that it is not possible to define a similar extension for the case of a negative mass Schwarzschild solution. This is consistent with the general expectation that degenerate metric spacetimes constructed within the HilbertPalatini Lagrangian framework should satisfy the energy conditions. 