INSTITUTE FOR THEORETICAL AND MATHEMATICAL PHYSICS

Lomonosov Moscow State University

# ITMP Seminar "A Puncture in the Euclidean Black Hole"

8 December 2021

Dear Colleagues,

We are pleased to announce that the next ITMP seminar will be held on Wednesday, Dec 8, at 18:00 (Moscow time). It will be arranged via zoom.

Speaker: prof. Nissan Itzhaki, Tel Aviv University

Title: A Puncture in the Euclidean Black Hole

Abstract:  We consider the backreaction of the winding zero mode on the cigar geometry. We focus on the case of the $SL(2,R)_k/U(1)$ cigar associated with e.g. the near-horizon limit of $k$ NS5 black-branes. We solve the equations of motion numerically in the large $k$ limit as a function of the amplitude of the winding mode at infinity.  We find that there is a critical amplitude $C_c=\exp(-\gamma/2)$ that admits a critical solution. The exact CFT description of the $SL(2,R)_k/U(1)$ cigar, in particular the FZZ duality, fixes completely the winding amplitude.  We find that in the large $k$ limit there is an exact agreement $C_c=C_{FZZ}$. The critical solution is a cigar with a puncture at its tip; consequently, the BH entropy is carried entirely by the winding condensate. We argue that, in the Lorentzian case, the information is ejected from the black hole through this puncture.

If you want to join the seminar please register here before 14:00, December 8 here.