dr. Skowera's seminar at SISSA

[Emanuele Tuillier Illingworth]

Dr. Jonathan Skowera (UZH - University of Zurich - 
jonathan.skowera at math.uzh.ch)

Białynicki-Birula decomposition of Deligne-Mumford stacks

Abstract: An action of the multiplicative group Gm can be used to 
decompose Deligne-Mumford stacks of stable maps,
thereby facilitating the computation of cohomology through the 
well-known Białynicki-Birula decomposition.
In particular, this process expresses the cohomology of the stack in 
terms of the cohomology of fixed point loci.
As one would hope, this property applies more broadly to any smooth, 
proper Deligne-Mumford stack over
an algebraically closed field of characteristic zero, and by an argument 
with motives, to any geometric
cohomology theory over Q. The only technical assumption is that the 
coarse moduli space of the stack be a scheme.

Thursday 28 June at 11.00 in lecture room 136 (SISSA Main building, I floor)


-- 
Dr. Emanuele Tuillier Illingworth
Secretary of the Mathematics Area
Building A, II floor, room 214
phone (+39) 040 37 87 598
fax (+39) 040 37 87 466
SISSA
Via Bonomea 265
34136
Trieste, ITALY
emanuele.tuillier at sissa.it