Found 4 result(s)

08.11.2017 (Wednesday)

Twisted BRST quantization and localization in supergravity

Regular Seminar Sameer Murthy (King's College London)

at:
13:15 KCL
room K4.31
abstract:

Supersymmetric localization is a powerful technique to evaluate a class of functional integrals in supersymmetric field theories. It reduces the functional integral over field space to ordinary integrals over the space of solutions of the off-shell BPS equations. The application of this technique to supergravity suffers from some problems, both conceptual and practical. I will discuss one of the main conceptual problems, namely how to construct the fermionic symmetry with which to localize. I will show how a deformation of the BRST technique allows us to do this. I will then sketch a computation of the one-loop determinant of the super-graviton that enters the localization formula for BPS black hole entropy.

21.01.2015 (Wednesday)

Polygon Seminar: Microscopic description of black holes in string theory

Triangular Seminar Sameer Murthy (King's)

at:
15:30 City U.
room BG03
abstract:

I will discuss the idea that a black hole in string theory is made up of a large number of microscopic constituents. For a class of black holes and black strings with extended supersymmetry, one has an exact counting formula for the number of states. I will sketch the idea and derivation of some of these formulas. I will then discuss applications to the AdS_2/CFT_1 and the AdS_3/CFT_2 correspondences.

08.01.2015 (Thursday)

Functional determinants, index theorems and exact quantum black hole entropy.

Regular Seminar Sameer Murthy (King's)

at:
14:00 QMW
room G.O. Jones 610
abstract:

I will discuss the exact quantum entropy of supersymmetric black holes as a gravitational functional integral in AdS2. In theories with eight supercharges, a computation of the exact entropy is possible using supersymmetric localization. I will discuss this technique, and describe the computation of functional determinants that can be computed using index theorems. I will then compare the exact gravitational formula to microscopic formulas coming from string theory.

06.11.2013 (Wednesday)

Quantum black hole entropy and the holomorphic prepotential

Regular Seminar Sameer Murthy (King's College)

at:
13:15 KCL
room S-1.04
abstract: