Transchromatic generalized character maps
  In "Generalized Group Characters and Complex Oriented Cohomology Theories", Hopkins, Kuhn, and Ravenel develop a way to study cohomology rings of the form E^*(BG) in terms of a character map. The character map can be interpreted as a map of cohomology theories beginning with a height n cohomology theory E and landing in a height 0 cohomology theory with a rational algebra of coefficients that is constructed out of E. In this paper we use the language of p-divisible groups to extend their construction for Morava E-theory so that the character map can land in every height t between 0 and n. 
Nathaniel J. Stapleton
math.AT