Seminario de categorías

Urs Schreiber, NYU Abu Dhabi and Czech Academy of Sciences, Prague

Resumen: I'll start with an exposition of higher equivariant principal bundle theory, using a convenient category/homotopy-theoretic approach, following the notes here:

ncatlab.org/schreiber/show/Higher+and+Equivariant+Bundles . By way of example and application, I'll then show how this provides a pleasantly transparent way to understand:

1. the CPT-twisting of equivariant K-theory, which has come to be known as the "10-fold way",

2. the neglected twisting of equivariant K-theory by "inner local systems" appearing inside orbi-singularities.

I'll close by briefly indicating how, under the interpretation of K-cohomology as D-brane charge, these two facts have remarkable consequences for the physics of exotic "defect branes" in string theory (arxiv.org/abs/2203.11838).

This is joint work with H. Sati. Slides will become available at:

ncatlab.org/schreiber/show/Anyonic+defect+branes+in+TED-K-theory .

Web: https://sites.google.com/im.unam.mx/seminario-de-categorias-unam/inicio