3 papers
math.CT2026
Kaluzhnin--Krasner embedding of precrossed modules
Maxime Culot, Bo Shan Deval
The Kaluzhnin--Krasner embedding establishes that, for a group extension, the middle group can be embedded into the wreath product of its kernel and cokernel. Recently, this constr…
math.CT2025
Intrinsic tensor products and a Ganea-type extension of the five-term exact sequence
Bo Shan Deval, Manfred Hartl, Tim Van der Linden
We define an intrinsic symmetric bi-right-exact (and for varieties, bi-cocontinuous) bilinear product on objects of a semi-abelian category, constructed as the cosmash product in t…
math.CT2023
Twisted Commutators and Internal Crossed Modules
Bo Shan Deval, Tim Van der Linden
We introduce a notion of relative commutator -- an important special case being commutators twisted by an action -- as a straightforward modification of the definition of the Higgi…