Videos

Victor Ostrik - Growth in tensor powers - IPAM at UCLA

Presenter
January 8, 2024
Abstract
Recorded 08 January 2024. Victor Ostrik of the University of Oregon, Mathematics, presents "Growth in tensor powers" at IPAM's Symmetric Tensor Categories and Representation Theory Workshop. Abstract: This talk is based on joint work with K. Coulembier, P. Etingof, D. Tubbenhauer. Let ?? be any group and let V be a nite dimensional representation of ?? over arbitrary eld. We consider tensor powers V n of V and their decompositions into indecomposable summands. Let bn(V ) be the total number of indecomposable summands in V n. We prove that lim n!1 n p bn(V ) = dim(V ): Similarly let dn(V ) be the number of indecomposable summands of V n with dimension not divisible by the characteristic of the eld. Then we dene (V ) := lim n!1 n p dn(V ): The real number (V ) is an interesting invariant of the representation V . Using theory of tensor categories we show that this invariant is ad- ditive (under direct sums), multiplicative and takes values in algebraic integers. Learn more online at: https://www.ipam.ucla.edu/programs/workshops/symmetric-tensor-categories-and-representation-theory/?tab=overview