The Harish-Chandra local character expansion and canonical dimensions for p-adic reductive groups
Abstract
A complex irreducible admissible representation of a reductive p-adic group is typically infinite-dimensional. To quantify the "size" of such representations, we introduce the concept of canonical dimension. To do so we have to discuss the Moy-Prasad filtrations. These are natural filtrations of the parahoric subgroups. Next, we relate the canonical dimension to the Harish-Chandra local character expansion, which expresses the distribution character of an irreducible representation in terms of nilpotent orbital integrals. Using this, we consider the wavefront set of a representation. This is an invariant the naturally arises from the local character expansion. We conclude by explaining why the canonical dimension might be considered a weaker but more computable alternative to the wavefront set.
Fermat's Last Tango, written in 2000 by Joanne Sydney Lessner and Joshua Rosenblum, tells the story, in words and music, of a 300 hundred-year-old mathematical mystery and the man who spent seven years trying to solve it.
This version was performed in early March 2023 by Oxford Mathematics students and fellow students from across the University. The venue was a lecture theatre in the Andrew Wiles Building, home to Oxford Mathematics and named after the mathematician who is the subject of the story.
Bootstrapping surface defects in the 6d N=(2,0) theories
Abstract
6d N=(2,0) superconformal field theories have natural surface operators similar in many ways to Wilson lines in gauge theories. In this talk, I will discuss how they can be studied using conformal bootstrap techniques, including connection to W-algebras and the so-called inversion formula, focusing on the limit of large central charge.