The Coxeter quotient of the fundamental group of a Galois cover of T \times T

2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/224094Let $X$ be the surface $\T\times\T$ where $\T$ is the complex torus. This paper is the third in a series, studying the fundamental group of the Galois cover of $X$ \wrt a generic projection onto $\C¶^2$. Van Kampen Theorem gives a presentation of the fundamental group of the complement of the branch curve, with 54 generators and more than 2000 relations. Here we introduce a certain natural quotient (obtained by identifying pairs of generators), prove it is a quotient of a Coxeter group related to the degeneration of $X$, and show that this quotient is virtually nilpotent.25 ppAlgebraic GeometryGroup Theory14J29The Coxeter quotient of the fundamental group of a Galois cover of T \times Ttext