Title: Emergent Symmetries in Ensemble Averages

Abstract: In It has been a long-standing conjecture that any exact global symmetry should be broken in theories of quantum gravity. This statement, however, is not necessarily true one we consider ensemble averages in theories of quantum gravity. In this talk, we will discuss concrete setup of ensemble averages of Narain CFTs and their holographic duals, to discuss the emergence of global symmetries in ensemble averages. We can extract the essence of this correspondence, and discuss emergence of global theories in ensemble averages in general. Such phenomena is ubiquitous and is actually closely related to the concept of the strong-to-weak symmetry breaking, which has been attracting attention in condensed mattter / statistical physics literature recently.