String Theory Journal Club

It has long been expected that the 3d Ising model can bethought of as a string theory, where one interprets the domain wallsthat separate up spins from down spins as two-dimensional stringworldsheets. I will revisit this "string theory" from the modern pointof view of higher form symmetries. The usual Ising Hamiltonian measuresthe area of these domain walls; as there is no explicit dependence onthe genus of the domain walls, it can be thought of as a string theorywith string coupling equal to unity. I discuss how to add new localterms to the Ising Hamiltonian that further weight each spinconfiguration by a factor depending on the genus of the correspondingdomain wall, resulting in a new 3d Ising model that has a tunable barestring coupling. I will use a combination of analytical and numericalmethods to analyze the phase structure of this model as this stringcoupling is varied. I will also describe statistical properties of thetopology of worldsheets and speculate on the prospects of using this newdeformation at weak string coupling to find a worldsheet description ofthe 3d Ising transition. Link: https://mpi-aei.zoom.us/j/91981837516. GQFI-WST is a common online seminar series organized by "Gravity, Quantum Fields and Information" (GQFI) group at the Max Planck Institute (Potsdam) and String Theory group at the University of Warsaw (WST).