On irreducible components of Rapoport-Zink spaces

Abstract

Under a mild condition, we prove that the action of the group of self-quasi-isogenies on the set of irreducible components of a Rapoport-Zink space has finite orbits. Our method allows both ramified and non-basic cases. As a consequence, we obtain some finiteness results on the representation obtained from the l-adic cohomology of a Rapoport-Zink tower.

42 pages; final version, some results in a quaternion unitary case are added, to appear in International Mathematics Research Notices