Joint Theory Seminar: Tomás Ortín

Title: Supergravity, superstrings and black-hole thermodynamics

Abstract: In this talk I will review work done over the last few years on alpha' corrections to black-hole solutions and the developments in black-hole thermodynamics it has driven. In particular, I will review the failure of the Iyer-Wald prescription to give a consistent entropy formula for the the black-hole solutions fo the first order in alpha' effective action of the heterotic superstring and how this problem can be fixed by treating appropriately the gauge symmetries of the theory. This treatment leads to interesting connections: generically, all dimensionful constants in the action (alpha', the embedding tensor...) can be seen as thermodynamical variables and they and their conjugate ("chemical") potentials occur in the Smarr formula and first law of the theory. The formalism can be extended to give a definition of scalar charges in stationary black hole solutions of supergravity theories that satifies a Gauss law and leads to a no-hair theorem.

Student session: 13:10