Holographic BCFTs and communicating black holes
Abstract
We study the AdS/BCFT duality between twodimensional conformal field theories with two boundaries and threedimensional antide Sitter space with two KarchRandall branes. We compute the entanglement entropy of a bipartition of the BCFT, on both the gravity side and the field theory side. At finite temperature this entanglement entropy characterizes the communication between two braneworld black holes, coupled to each other through a common bath. We find a Page curve consistent with unitarity. The gravitational result, computed using doubleholographically realized quantum extremal surfaces, matches the conformal field theory calculation.At zero temperature, we obtain an interesting extension of the AdS_{3}/BCFT_{2} correspondence. For a central charge c, we find a gap (" separators=",c/16 c/12 ) in the spectrum of the scaling dimension ∆_{bcc} of the boundary condition changing operator (which interpolates mismatched boundary conditions on the two boundaries of the BCFT). Depending on the value of ∆_{bcc}, the gravitational dual is either a defect global AdS_{3} geometry or a single sided black hole, and in both cases there are two KarchRandall branes.
 Publication:

Journal of High Energy Physics
 Pub Date:
 August 2021
 DOI:
 10.1007/JHEP08(2021)003
 arXiv:
 arXiv:2104.07039
 Bibcode:
 2021JHEP...08..003G
 Keywords:

 AdSCFT Correspondence;
 Black Holes;
 Conformal Field Theory;
 High Energy Physics  Theory
 EPrint:
 43 pages, 9 figures, published version in JHEP