Events Daily

Friday, December 9, 2022
      

Entanglement entropy in (1+1)-d with defects
Fei Yan, Rutgers
Event Type: HEP Seminar
Time: 11:00 AM - 12:00 PM
Location: 726 Broadway, 940, CCPP Seminar
Abstract: In this talk I will explore perspectives of quantum entanglement in (1+1)-d systems in presence of defects. The talk consists of two parts. In the first part, I will talk about the ground state entanglement entropy for 1d quantum spin chains with defects, using the transverse field Ising model and the three-state Potts model as examples. In the second part, I will comment on the field theoretical replica trick approach to study entanglement entropy in such systems.

Link to the Event Video


Holography from Singular Supertranslations on a Black Hole Horizon
Sangmin Choi, École Polytechnique
Event Type: Informal HEP Talk
Time: 2:00 PM - 3:00 PM
Location: 726 Broadway, 940, CCPP Seminar
Abstract: We investigate the standard and dual BMS supertranslation generators on the black hole horizon and draw some conclusions about black hole physics. Recently, it has been shown that in addition to the conventional BMS supertranslation symmetries, there exists another infinite set of magnetic asymptotic symmetries that are referred to as dual BMS supertranslations. We show that the Dirac bracket between these generators exhibits a central term when the parameter functions have singularities in the complex stereographical coordinates on the sphere. Such singularities are related to Dirac-string-like configurations in the bulk, and should therefore be included in the set of acceptable transformations. We then demonstrate that this anomalous central term can be removed by including an appropriate gravitational Chern-Simons theory on the horizon. This implies that consistency of the asymptotic symmetry algebra requires a new structure on the horizon.

Link to the Event Video