4-manifolds and exotic group presentations

Meeting ID: 916 5855 1117
Password: as before.
Contact: Aru Ray and Tobias Barthel.

Two presentations for a group G which have the same deficiency are called exotic if the corresponding presentation complexes are not homotopy equivalent. It was not until the 1970s that the first examples of exotic presentations were found. In the 1980s, Kreck and Schafer went on to use these exotic presentations to construct the first and only known examples of smooth closed 4-manifolds which are stably diffeomorphic but not homotopy equivalent.

In this talk, I will present some new exotic group presentations as well as some questions about 4-manifolds which I hope they will be able to answer. This is work in progress.