Hosted by: Niklas Mueller

It has long been suspected that symmetries in quantum gravity are highly constrained. In this talk I will describe joint work with Hirosi Ooguri, where we use the power of the AdS/CFT correspondence to prove three conjectures of this type: that there are no global symmetries, that there must be objects transforming in all representations of any gauge symmetry, and that any gauge group must be compact. Real world implications include the existence of magnetic monopoles and neutrinoless double beta decay, although we so far are unable to give estimates for when these should be seen. An important point, which we dwell on at length, is the proper definition of gauge and global symmetries in quantum field theory.