Sam P. Fisher

activity

20222026

most citedThe Hanna Neumann Conjecture for graphs of free groups with cyclic edge groups

1 citations · 1 across the 8 of their papers we have counts for

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math.GR2025

Novikov cohomology, finite domination, and cohomological dimension

Sam P. Fisher

We introduce the $Σ^{*}$ -invariant of a group of finite type, which is defined to be the subset of non-zero characters $χ \in H^{1} (G; R)$ with vanishing associated top-d…

math.GR2025

Virtual fibring of Poincaré-duality groups

Sam P. Fisher, Giovanni Italiano, Dawid Kielak

We show that a RFRS Poincaré-duality group $G$ admits a virtual epimorphism to the integers whose kernel is itself a Poincaré-duality group over every field if and only if the $L^2…