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SUMMARY:K3 surfaces with non-symplectic involution and compact G2-manifold
 s - Alexei Kovalev\, Cambridge
DTSTART:20110223T160000Z
DTEND:20110223T170000Z
UID:TALK25741@talks.cam.ac.uk
CONTACT:Ivan Smith
DESCRIPTION:I will describe a large new class of quasiprojective complex a
 lgebraic threefolds and their application to constructing many new example
 s of compact Ricci-flat 7-manifolds with holonomy G_2\, via the connected-
 sum\nmethod. The construction requires gluing two `matching' pieces\, each
  one being a product of a threefold and a circle. The threefolds are obtai
 ned using the theory of K3 surfaces with non-symplectic involution due to 
 Nikulin. The relation will also be explained between algebraic invariants 
 of K3 surfaces and the `geography' of Betti numbers of the new and some pr
 eviously known compact G_2-manifolds. Joint work with N.-H. Lee.
LOCATION:MR4
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