HET seminar: Yuri Makeenko

Speaker: Yuri Makeenko

Title: Effective string beyond the Liouville action

Abstract: I describe quantization of bosonic string about the mean-field ground state, which is shown to be stable in the target-space dimension $2<d<26$ contrary to the usual classical ground state which is stable only for $d<2$, and discuss how this resolves some old problems with strings.
I compute the string susceptibility index $\gamma_{\rm str}$ in the mean-field approximation and demonstrate that it differs from KPZ-DDK.
I show that the total central charge equals zero in the mean-field approximation and argue that fluctuations about the mean field do not spoil conformal invariance.
Using Pauli-Villars regularization, I compute a correction to the Liouville action by going beyond the conformal anomaly and accounting for quadratic divergences.
I speculate on how the associated conformal field theory may look like.