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math.AT2025
Small Value of cohomological dimension of group homomorphisms
Nursultan Kuanyshov
We give the characterisation of cohomological dimension of group homomorphisms. In particular, we show the analogue of the Stallings-Swan theorem in the case of group epimorphisms.
math.AT2025
On numerical invariants of retraction map
Nursultan Kuanyshov
We introduce a notion of retraction between continuous maps of topological spaces and study the behavior of several numerical invariants under such retractions. These include (co)h…