Authors: Arnautov Vladimir, Topala A. G.
Abstract
Let $G$ a free group, generated by the set $X$, which contains more than one element. Then the lattice of all group topologies of $G$ is not modular.
Institutul de Matematică Academia de Ştiinţe a Moldovei
str. Academiei 5, Chişinău, MD-2028 Moldova