HOPF HEAPS AND HOPF ALGEBRAS OF TRANSLATIONS

Grunspan and Schauenburg have proven that quantum torsors (introduced by the former) are closely connected with Hopf-Galois objects. In this talk, I will present, in part, the dualisation of this connection and, in part, a new characterisation of quantum cotorsors, or Hopf heaps, in terms of Galois-type actions of the associated translation Hopf algebras (not available in the dual setup). The talk is based on a joint work with Małgorzata Hryniewicka.