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.CT2026
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.CT2024
A universal Kaluzhnin--Krasner embedding theorem
Bo Shan Deval, Xabier GarcÃa-MartÃnez, Tim Van der Linden
Given two groups and , the Kaluzhnin--Krasner universal embedding theorem states that the wreath product acts as a universal receptacle for extensions from to $…