Next Algebra Seminar: Bianca Marchionna (Bielefeld University/Milano-Bicocca)

Bianca Marchionna (Bielefeld University/Milano-Bicocca) will be giving an in-person talk in our algebra seminar next week, Wednesday 14 of February 2024, at 15:00 (tea/coffee/biscuits 14:30).

You can attend by joining us in INB3305 or via Teams. If you want more information about it, please let us know via algebraseminarUoL@gmail.com.

All welcome!

Title: Double-coset zeta functions and groups acting on trees

Abstract: 

The double-coset zeta functions have been recently introduced by I. Castellano, G. Chinello and T. Weigel as a possible tool for studying asymptotic properties of a locally compact group G. These functions are defined by Dirichlet series, with each series corresponding to a compact open subgroup U of G. They arise from counting the U-double-cosets of G with a prescribed Haar measure.

The seminar focuses on the favourable case of G acting on a locally finite tree. If the action is either “sufficiently transitive” or “(P)-closed”, one can reduce the study of the series to handle combinatorial problems involving local data of the actions.

We also present a criterion on these groups to relate their Euler-Poincaré characteristic with the value of the above-mentioned zeta functions at -1.