Periodic-point structures on parametrized spectra: An application of rigidity

Abstract

The bicategory of parameterized spectra has a remarkably rich structure. In particular, it is possible to take traces in this bicategory, which give classical invariants that count fixed points. We can also take equivariant traces, which give significant generalizations of the classical invariants that count periodic points. Unfortunately, the existence of these traces in general depends on technical statements about the bicategory that can be difficult to verify directly. In this paper, we demonstrate the effectiveness of two tools -- rigidity and deformable functors -- by using them establish the structure we need to take these equivariant traces and to construct periodic-point invariants in a formal way.