# Manuel Krannich: The Disc-structure space

**Time: **
Thu 2022-02-10 14.15 - 16.00

**Location: **
Zoom

**Video link: **
Meeting ID: 921 756 1880

**Participating: **
Manuel Krannich (University of Münster)

**Abstract:** The classical approach to studying the enriched category of manifolds and their diffeomorphisms is to first compare it to a simplified category of block-manifolds and then compare the latter to the category of Poincaré complexes. The information lost in each of these steps is encoded in certain structure spaces that are expressible—in a certain range—in terms of *K*- and *L*-theory. More recent developments related to manifold calculus and factorisation homology suggest a different approach, namely to compare the category of manifolds to a variant of the derived category of modules over the little *d*-discs operad. Again, this amounts to studying certain structure spaces that encode the difference: the Disc-structure spaces. In this talk, I will explain the above and describe aspects of joint work with A. Kupers in which we show that, in most cases, these Disc-structure spaces are nontrivial infinite loop spaces that depend only little on the underlying manifolds.