We will introduce the notion of $G$-Higgs bundle and focus in a particular case which gives us much more information, that of $G$ being the isometry group of a Hermitian symmetric space. In that case, Milnor Wood inequality will bound the Toledo invariant, and when $G$ is of tube type as well,...
It has been several attempts to generalize the ordinary commutative algebraic geometry to the noncommutative situation. The main problem in the direct generalization, is the lack of localization of noncommutative $k$-algebras, $k$ algebraically closed. This can only be done for Ore sets, and does...
Xosé M. Masa
(Universidade de Santiago de Compostela)
Date:
Friday, 30 January, 2009 - 14:30
Venue:
sala 0.03
Trata-se de apresentar uma cohomologia associada a folheações sem nenhuma estrutura diferenciable, e que para folheações diferenciables suficientemente regulares coincida com a cohomologia de de Rham.
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Moduli spaces of polygons have been, since the ’90s, a widely studied example of K¨ahler reduction. The hyperpolygons spaces are the non-compact hyperK¨ahler quotient analogue to polygons spaces.
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We show how the theory of Higgs bundles can be applied to the study of the following geometric problem: When can a maximal Sp(4,R)-representation of a surface group be deformed to a representation which factors through a proper reductive subgroup of Sp(4,R)?