Quantum Mathematics Seminar: Xiao Han (Queen Mary)

Quantum Maths Seminar, external speaker.

Speaker: Xiao Han (Queen Mary University, London)

Title: Hopf-Galois Extensions and Twisted Hopf algebroids

Abstract: We show that the Ehresmann-Schauenburg bialgebroid of a quantum principal bundle P or Hopf Galois extension with structure quantum group H is in fact a left Hopf algebroid CL(P,H). We look cleft extension of a certain `associative type' where ▷ is an actual action. In this case also, we show that the associated left Hopf algebroid has an antipode obeying our minimal axioms. We show that if CL is any left Hopf algebroid then so is its cotwist CL^ς as an extension of the previous bialgebroid Drinfeld cotwist theory.

One-hour in-person talk