Theoretical Physics Seminar: Jacopo Sisti

  • Date: –15:00
  • Location:
  • Lecturer: Jacopo Sisti
  • Organiser: Luca Cassia
  • Contact person: Luca Cassia
  • Seminarium

Entanglement Entropy and Central Charges of 2d Boundaries and Defects

In this talk, we discuss some results regarding the entanglement entropy and the defect central charges of two-dimensional boundaries and defects. First, we consider the AdS_4/BCFT_3 correspondence proposed by Takayanagi in which we study the holographic entanglement entropy of spatial regions with arbitrary shape. Analytic expressions for some smooth domains are reproduced, including the one for a disk disjoint from the boundary. When the entangling curve intersects the boundary, a logarithmic divergent contribution occurs. We find its coefficient is determined by a function that contains information about the boundary central charges. In the second part, we discuss half-BPS surface defects in 4d N=2 supersymmetric theories. We show how to extract the defect central charges from supersymmetric localization and the AGT correspondence. Some of our results for defect central charges agree with those obtained previously via holography, showing that the latter are not just large-N and/or strong-coupling limits, but are exact.