3 papers
math.QA2026
Coquasi-bialgebroids and cocycle twisting
Xiao Han, Shahn Majid
We introduce coquasi-bialgebroids over a noncommutative base algebra. Using Takeuchi's \(\times_B\)-coalgebra formalism, we require the coproduct to remain an algebra map into the…
math.QA2025
Quantum jet Hopf algebroids by cotwist
Xiao Han, Shahn Majid
We introduce a cotwist construction for Hopf algebroids that also entails cotwisting or `quantisation' of the base and which is dual to a previous twisting construction of P. Xu. W…
math.QA2024
*-Hopf algebroids
Edwin Beggs, Xiao Han, Shahn Majid
We introduce a theory of -structures for bialgebroids and Hopf algebroids over a -algebra, defined in such a way that the relevant category of (co)modules is a bar category.…