Noninvertible Symmetry-Resolved Affleck-Ludwig-Cardy Formula and Entanglement Entropy from the Boundary Tube Algebra

Phys Rev Lett. 2024 Dec 20;133(25):251602. doi: 10.1103/PhysRevLett.133.251602.

Abstract

We derive a refined version of the Affleck-Ludwig-Cardy formula for a 1+1D conformal field theory, which controls the asymptotic density of high energy states on an interval transforming under a given representation of a noninvertible global symmetry. We use this to determine the universal leading and subleading contributions to the noninvertible symmetry-resolved entanglement entropy of a single interval. As a concrete example, we show that the ground state entanglement Hamiltonian for a single interval in the critical double Ising model enjoys a Kac-Paljutkin H_{8} Hopf algebra symmetry when the boundary conditions at the entangling points are chosen to preserve the product of two Kramers-Wannier symmetries, and we present the corresponding symmetry-resolved entanglement entropies. Our analysis utilizes recent developments in symmetry topological field theories.