Seminario de Teoría de grupos UAM-ICMAT

Ponente: Mark Shusterman

Título:  Howson's Theorem

Miércoles 11 de octubre de 2017

11:30, Aula Gris 1, ICMAT 

Resumen: A classical result of Howson says that the intersection of two finitely generated subgroups of a free group is finitely generated. This result has been generalized to surface groups, limit groups, free pro-p groups, and established in many other cases as well. Furthermore, the problem of bounding the number of generators of the intersection received much attention.

I will present a very simple proof of Howson’s theorem, and show how the result extends to surface groups, and various pro-p groups (such as Galois groups of p-adic field extensions).

Time permitting, I will also discuss the problem of obtaining bounds on the number of generators of the intersection.