Representation varieties of finite index subgroups of Baumslag–Solitar groups

Representation varieties of finite index subgroups of Baumslag–Solitar groups are investigated. It is proved that all irreducible components of the representation variety of a finite index subgroup of a Baumslag–Solitar group are birational isomorphic to irreducible components of the representation variety of some another Baumslag–Solitar group.