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Topology and Geometry Seminar

Wed., Oct. 18, 2023 2:00 p.m.

Location: CL 305

Speaker: Ben Willliams, University of British Columbia

Title: Classifying involutions of Azumaya algebras (99 kB) PDF file


This is joint work with Uriya First. Azumaya algebras are objects that are locally isomorphic to matrix algebras—over a topological space X, they are bundles of matrix algebras. If the base space X is endowed with a self-map of order 2 (which may be trivial) t : XX, then a t-involution of an Azumaya algebra A over X is a map s : AA of order 2 that preserves addition, reverses multiplication, and is compatible with t. These involutions are analogues of transposition or hermitian conjugation of matrix algebras. I will explain a coarse classification of these involutions into types, depending on the base involution t, and produce some exotic examples.


Topology and Geometry Seminar: