Ulrich Kraehmer: "What is a quantum symmetry?"
Talk given as part of Categories Logic and Physics Scotland: http://conferences.inf.ed.ac.uk/claps....
Since the 1980s, algebraists studied quantum groups (Hopf algebras) as generalised symmetries, and they extended various concepts and results from group theory to quantum groups. After giving a small survey of this story, I will explain a paper with Angela Tabiri in which we show that planar curves have way more quantum symmetries than classical ones, and also more than we expected.