Carissimi,
vi segnalo i due seminari che ci saranno giovedì (Alex Suciu e Stefan Papadima) ed il seminario baby-geometri di mercoledì (Alex Suciu).
Buona giornata,
Filippo
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SEMINARIO BABY GEOMETRI
MERCOLEDÌ 28 MAGGIO 2014 14:30 (seminario Baby-geometri) Alex Suciu (Northeastern University, Boston) Topology of hyperplane arrangements
ABSTRACT: Much of the fascination with arrangements of complex hyperplanes comes from the rich interplay between the combinatorics of its intersection lattice and the algebraic topology of its complement. A key bridge between the two is provided by the geometry of two sets of algebraic varieties associated to the complement: the resonance varieties of the cohomology ring and the characteristic varieties of the fundamental group.
SEMINARIO DI ALGEBRA, TOPOLOGIA E COMBINATORIA
GIOVEDI' 29 MAGGIO 2014 16:00-17:00, Sala Riunioni (Dip. Matematica) Alex Suciu (Northeastern University, Boston) Combinatorial covers, abelian duality, and propagation of resonance
ABSTRACT: We revisit and generalize a result of Eisenbud, Popescu, and Yuzvinsky, which says that the resonance varieties of a hyperplane arrangement complement propagate. It turns out that the topological underpinning for this phenomenon is a certain abelian duality property, coupled with the minimality property enjoyed by arrangement complements and related spaces, such as Cohen-Macaulay toric complexes. The key ingredient in the proof is a general, cohomological vanishing result for spaces that admit suitable `combinatorial' covers.
This is joint work with Graham Denham and Sergey Yuzvinsky.
SEMINARIO DI ALGEBRA, TOPOLOGIA E COMBINATORIA
GIOVEDI' 29 MAGGIO 2014 17:00-18:00, Sala Riunioni (Dip. Matematica) Stefan Papadima (IMAR) Milnor fibrations of arrangements and modular inequalities
ABSTRACT: A central question in the theory of complex hyperplane arrangements is to determine whether the characteristic polynomial of the algebraic monodromy acting on the rational homology of the associated Milnor fiber may be described solely in terms of the underlying combinatorics. I will discuss an approach based on the associated resonance varieties in positive characteristic.
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Prossimi seminari:
GIOVEDI 12 GIUGNO 2014 ore 17:00-19:00, sala Riunioni Giulia Saccà (Princeton University)
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Il programma completo dei seminari si trova alla pagina: http://www.dm.unipi.it/~gaiffi/homepageseminario/ Sulla pagina è anche possibile scaricare le slides dei precedenti seminari.