1,720,987 research outputs found
Paving Springer fibers for E7
No full textWe study the existence of a paving by affine spaces of Springer fibers. In particular, we prove that in the case of simple groups not of type E8 such pavings exist
A differential algebra and the homotopy type of the complement of a toric arrangement
No full textWe show that the rational homotopy type of the complement of a toric arrangement is completely determined by two sets of discrete data. This is obtained by introducing a differential graded algebra over Q whose minimal model is equivalent to the Sullivan minimal model of A
On projective wonderful models for toric arrangements and their cohomology
Full text linkThis paper is divided into two parts. The first part is a brief survey, accompanied by concrete examples, on the main results of the papers (De Concini and Gaiffi in Adv Math 327:390–09, 2018; Algebr Geom Topol 19(1):503–532, 2019): the construction of projective models of toric arrangements and the presentation of their cohomology rings by generators and relations. In the second part we focus on the notion of well-connected building set that appears in the cohomological computations mentioned above: we explore some of its properties in the more general context of arrangements of subvarieties of a variety X
On some modules of covariants for a reflection group
Full text linkLet g be a simple Lie algebra with Cartan subalgebra h and Weyl group W. We build up a graded isomorphismh⊗H⊗hW →g⊗gg ofgg ∼=S(h)W- modules, where H is the space of W-harmonics. In this way we prove an enhanced form of a conjecture of Reeder for the adjoint representation
A GENERALIZED STEINBERG SECTION AND BRANCHING RULES FOR QUANTUM GROUPS AT ROOTS OF 1
No full textn this paper we construct a generalization of the classical Steinberg section for the quotient map of a semisimple group with re- spect to the conjugation action. We then give various applications of our result including the construction of a sort of Gelfand–Zeitlin basis for a generic irreducible representation of Uq(GL(n)) when q is a primitive odd root of unity
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