2 papers
math.CT2026
Exchange theorems and coherent duality in six functors
William Fisher
We define the notion of an exchange theorem and show that any two functors satisfying an exchange theorem are canonically related via twisted norm maps. This is done by identifying…
math.GT2022
Contractible complexes and non-positive immersions
William Fisher
We provide examples of contractible complexes which fail to have non-positive immersions and weak non-positive immersions, answering a conjecture of Wise in the negative.