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 KCLroom 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 QMWroom 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 KCLroom S-1.04 abstract: