Entanglement in String Theory and 2D Yang Mills
Gabriel Wong (UVirginia/KITP)
We consider entanglement entropy in the Gross-Taylor model: the topological string theory dual to two-dimensional Yang-Mills theory at large N. The string diagrams that contribute to the entanglement entropy describe open strings with endpoints anchored to the entangling surface. We develop a canonical theory of these open strings, and describe how closed strings are divided into open strings at the level of the Hilbert space, giving a precise state-counting interpretation to the entropy. We therefore reinterpret Gross and Taylor's Ω-point singularity as an entangling surface on which open strings end: an E-brane.