Twisted invariant theory for reflection groups
  Let $G$ be a reflection group acting on a vector space $V$ and let $\gamma$ be an automorphism of $V$ normalising $G$. We study how $\gamma$ acts on invariants and covariants (for various representations) of $G$, and properties of its eigenspaces. 
C\'edric Bonnaf\'e (LM-Besan\c{c}on), Gus Lehrer, Jean Michel (LAMFA,   IMJ)