Dawid Kielak shows that a finitely generated residually finite rationally solvable (or RFRS) group is virtually fibred if a homological obstruction (the first L²-Betti number) vanishes. Kielak discusses his new proof, which in particular reproves the analogous result of Ian Agol for fundamental groups of 3-manifolds. Image courtesy of Dawid Kielak.

Image courtesy of interviewee. March 31, 2021