Entropy, determinants and zeta values

Abstract: It was observed in the 1980's that the entropy of an action by two or more commuting automorphisms on a compact abelian group is sometimes given by a zeta- or L-value. For example zeta(3) arises in this way. In the talk I will report on joint work with Thu Hà Trieu, which at least for expansive actions explains the deeper reason for these observations by a combination of operator algebra theory, in particular the theory of their determinants, K-theory and cyclic and Deligne cohomology. The talk is addressed to a general audience and will not go into technical details. Instead we will sketch the relevant theories and explain how to fit them together for our purpose.

algebraic geometrydifferential geometrysymplectic geometry

Audience: researchers in the topic

Geometria em Lisboa (IST)

Series comments: To receive the series announcements, which include the
Zoom access password*, please register in
math.tecnico.ulisboa.pt/seminars/geolis/index.php?action=subscribe#subscribe
*the last announcement for a seminar is sent 5 hours before the seminar.

Geometria em Lisboa video channel: educast.fccn.pt/vod/channels/bu46oyq74