Marc Kegel: Unrecognizable manifolds and uncomputable invariants.

In this talk, we will discuss some recent results on the limits of computation in topology, with a particular focus on dimension four. We will explain what it means for a manifold to be algorithmically unrecognizable and how undecidable problems in group theory give rise to such examples. We will then explore the consequences for the computability of topological invariants.

Zoom link: https://us06web.zoom.us/j/86570145006?pwd=fqSKabceyPQszxT6xzP3bokpg5c4xT.1
Meeting ID: 865 7014 5006
Passcode: 287154