Cohomology of affine Artin groups and applications

dc.creatorCallegaro, Filippo
dc.creatorMoroni, Davide
dc.creatorSalvetti, Mario
dc.date2007-05-19
dc.date.accessioned2026-07-07T08:02:32Z
dc.date.available2026-07-07T08:02:32Z
dc.descriptionThe result of this paper is the determination of the cohomology of Artin groups of type A_n, B_n and \tilde{A}_{n} with non-trivial local coefficients. The main result is an explicit computation of the cohomology of the Artin group of type B_n with coefficients over the module \Q[q^{\pm 1},t^{\pm 1}]. Here the first (n-1) standard generators of the group act by (-q)-multiplication, while the last one acts by (-t)-multiplication. The proof uses some technical results from previous papers plus computations over a suitable spectral sequence. The remaining cases follow from an application of Shapiro's lemma, by considering some well-known inclusions: we obtain the rational cohomology of the Artin group of affine type \tilde{A}_{n} as well as the cohomology of the classical braid group {Br}_{n} with coefficients in the n-dimensional representation presented in \cite{tong}. The topological counterpart is the explicit construction of finite CW-complexes endowed with a free action of the Artin groups, which are known to be K(π,1) spaces in some cases (including finite type groups). Particularly simple formulas for the Euler-characteristic of these orbit spaces are derived.
dc.description21 pages, 4 figures
dc.identifierhttps://arxiv.org/abs/0705.2823
dc.identifierhttp://arxiv.org/abs/0705.2823
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/129256
dc.subjectAlgebraic Topology
dc.subject20J06; 20F36
dc.titleCohomology of affine Artin groups and applications
dc.typetext

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