Quantum Torsors with Fewer Axioms

  title={Quantum Torsors with Fewer Axioms},
  author={Peter Schauenburg},
We give a definition of a noncommutative torsor by a subset of the axioms previously given by Grunspan. We show that noncommutative torsors are an equivalent description of Hopf-Galois objects (without specifying the Hopf algebra). In particular, this shows that the endomorphism θ featuring in Grunspan's definition is redundant.