High Energy Theory Seminar

Entanglement is an important property of quantum systems, but its precise definition in field theory poses some challenges. The problem is particularly acute in gauge theories and string theory, where extended objects such as Wilson loops and strings preclude any local factorization of the Hilbert space. As a model of this problem, I will discuss entanglement in two-dimensional Yang-Mills theory and its large-N description as a string theory due to Gross and Taylor. I will show how entanglement in this theory fits naturally within the framework of extended topological quantum field theory developed by Moore and Segal. Entanglement entropy in the closed string theory counts configurations of open strings whose endpoints are anchored on a codimension-2 surface we call the entanglement brane. Based on arXiv:1610.01719 and forthcoming work with Gabriel Wong.