Matthew Reece, Harvard University

"No Global Symmetries, with Applications to Axion Physics"

Abstract: There are reasons to believe that consistent quantum gravity theories do not admit exact global symmetries. This claim has surprisingly strong implications, some of which are relevant for particle physics and cosmology. I will discuss some recent variations on this theme, including the absence of Chern-Weil symmetries (with applications to axion physics) and the relationship to a complete spectrum of charged objects.