title: Universality of Corner Entanglement in Conformal Field Theories.
abstract: We study the contribution to the entanglement entropy of (2+1)-dimensional conformal field theories (CFTs) coming from a sharp corner in the entangling surface. This contribution is encoded in a function a(θ) of the corner opening angle, and was recently proposed as a measure of the degrees of freedom in the underlying CFT. We show that the ratio a(θ)/C(T), where C(T) is the central charge in the stress tensor correlator, is an almost universal quantity for a broad class of theories including various higher-curvature holographic models, free scalars, and fermions, and Wilson-Fisher fixed points of the O(N) models with N=1,2,3. Strikingly, the agreement between these different theories becomes exact in the limit θ→π, where the entangling surface approaches a smooth curve. We thus conjecture that the corresponding ratio is universal for general CFTs in three dimensions.
authors.affiliation: Instituto de Física Teórica UAM/CSIC, Nicolás Cabrera, 13-15, C.U. Cantoblanco, E-28049 Madrid, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Bueno
authors.affiliation: Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, Canada.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Myers
authors.affiliation: Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, Canada.
authors.forename: William
authors.initials: W
authors.lastname: Witczak-Krempa