TPPC weekly seminar (in-person): Steve Abel - "UV/IR mixing, nonrenormalisation theorems and new approaches to naturalness "

Wednesday 15 Jan 2025, 12:30 → 13:45 Europe/London

Abstract: In this talk I describe recent progress in understanding the additional constraints that UV/IR mixing places on a theory in order for a consistent EFT to emerge. As an example that can be treated rigorously, we consider the UV/IR mixing associated with modular invariance in closed strings, and show that this yields a novel set of supertrace constraints which are associated with possible decompactification limits. These constraints are similar to the nonrenormalisation theorems of supersymmetry but they are applicable in full generality. I discuss the various phenomenological consequences that arise including the lack of any power law running, and the apparent UV fixed-point behaviour. The talk will be pedagogical.