Tame complexes, L2-invariants and the Hanna Neumann conjectureMPIM

by Ismael Morales (MPIM)

Thursday Oct 23, 2025, 4:30 PM → 6:00 PM Europe/Berlin

MPIM, Vivatsgasse, 7 - Seminar Room (Max Planck Institute for Mathematics)

Oberseminar Differentialgeometrie

I will talk about a joint article with Sam Fisher where we address the Hanna Neumann conjecture for limit groups. Roughly, its original formulation states that if G is a free group and H and K are subgroups of rank N and M, respectively; then the rank of the intersection is at most the product NM. Combining ideas of Antolin, Jaikin, Wilton and Wise (among others); we establish an analogous statement for any limit group by studying the geometry of its subgroups in relation to certain induced maps in L2-homology.