# Codes and Expansions (CodEx) Seminar

## Mikhail Ganzhinov (Aalto University)Infinite families of optimal biangular line packings

Two infinite families of biangular line packings can be constructed from transitive actions of finite groups $\operatorname{SL}(2, 2^{2k+1})$ and $\operatorname{SL}(2, 3^k)$, $k = 1, 2, \ldots$. These line packings achieve equality in the real and complex versions of the second Levenshtein's bound, depending on the infinite family. The talk will mainly focus on the real infinite family which is related to groups $\operatorname{SL}(2, 2^{2k+1})$.