Events

Date: 26 February 2026   Time: 13:00 - 14:00     

Location: MB-503

This talk is about algorithms for iterations of linear maps. Given a linear map in the form of a matrix M with rational entries, and some point x, what can we say algorithmically about the sequence Mx, M^2 x, M^3 x, … . In particular, is there an algorithm that decides whether one of the points in the trajectory is inside a given half-space? This is a long-standing open problem, which is related to diophantine properties of some algebraic numbers. After giving a general background, and illustrating the difficulties, I will tell you about some recent progress on variants of this problem.