a1 Department of Mathematics, Duke University, Box 90320, Durham, NC 27708-0320, USA (email: [email protected])
Desingularized fiber products of semi-stable elliptic surfaces with Hetale3=0 are classified. Such varieties may play a role in the study of supersingular threefolds, of the deformation theory of varieties with trivial canonical bundle, and of arithmetic degenerations of rigid Calabi–Yau threefolds.
(Received November 21 2007)
(Accepted June 04 2008)
2000 Mathematics Subject Classification
Partial support by the NSF (DMS-0200012) and NSA (MDA904-97-1-0041) is gratefully acknowledged.