Faster FPT Algorithm for Graph Isomorphism Parameterized by Eigenvalue   Multiplicity
  We give a $O^*(k^{O(k)})$ time isomorphism testing algorithm for graphs of eigenvalue multiplicity bounded by $k$ which improves on the previous best running time bound of $O^*(2^{O(k^2/\log k)})$. 
Vikraman Arvind and Gaurav Rattan
cs.CC