A transchromatic proof of Strickland's theorem
  In "Morava E-theory of symmetric groups", Strickland proved that the Morava E-theory of the symmetric group has an algebro-geometric interpretation after taking the quotient by a certain transfer ideal. This result has influenced most of the work on power operations in Morava E-theory and provides an important calculational tool. In this paper we give a new proof of this result as well as a generalization by using transchromatic character theory. The character maps are used to reduce Strickland's result to representation theory. 
Tomer M. Schlank, Nathaniel Stapleton
math.AT