Displaying similar documents to “Transgression and Clifford algebras”

The existence of equivariant pure free resolutions

David Eisenbud, Gunnar Fløystad, Jerzy Weyman (2011)

Annales de l’institut Fourier

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Let A = K [ x 1 , ⋯ , x m ] be a polynomial ring in m variables and let d = ( d 0 < ⋯ < d m ) be a strictly increasing sequence of m + 1 integers. Boij and Söderberg conjectured the existence of graded A -modules M of finite length having pure free resolution of type d in the sense that for i = 0 , ⋯ , m the i -th syzygy module of M has generators only in degree d i . This paper provides a construction, in characteristic zero, of modules with this property that are also G L ( m ) -equivariant. Moreover, the construction...

On the cohomology of vector fields on parallelizable manifolds

Yuly Billig, Karl-Hermann Neeb (2008)

Annales de l’institut Fourier

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In the present paper we determine for each parallelizable smooth compact manifold M the second cohomology spaces of the Lie algebra 𝒱 M of smooth vector fields on M with values in the module Ω ¯ M p = Ω M p / d Ω M p - 1 . The case of p = 1 is of particular interest since the gauge algebra of functions on M with values in a finite-dimensional simple Lie algebra has the universal central extension with center Ω ¯ M 1 , generalizing affine Kac-Moody algebras. The second cohomology H 2 ( 𝒱 M , Ω ¯ M 1 ) classifies twists of the semidirect product...

The Hochschild cohomology ring of the singular cochain algebra of a space

Katsuhiko Kuribayashi (2011)

Annales de l’institut Fourier

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We determine the algebra structure of the Hochschild cohomology of the singular cochain algebra with coefficients in a field on a space whose cohomology is a polynomial algebra. A spectral sequence calculation of the Hochschild cohomology is also described. In particular, when the underlying field is of characteristic two, we determine the associated bigraded Batalin-Vilkovisky algebra structure on the Hochschild cohomology of the singular cochain on a space whose cohomology is an exterior...

Coalgebraic Approach to the Loday Infinity Category, Stem Differential for 2 n -ary Graded and Homotopy Algebras

Mourad Ammar, Norbert Poncin (2010)

Annales de l’institut Fourier

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We define a graded twisted-coassociative coproduct on the tensor algebra the desuspension space of a graded vector space V . The coderivations (resp. quadratic “degree 1” codifferentials, arbitrary odd codifferentials) of this coalgebra are 1-to-1 with sequences of multilinear maps on V (resp. graded Loday structures on V , sequences that we call Loday infinity structures on V ). We prove a minimal model theorem for Loday infinity algebras and observe that the Lod ∞ category contains the L ∞ ...

Second cohomology classes of the group of C 1 -flat diffeomorphisms

Tomohiko Ishida (2012)

Annales de l’institut Fourier

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We study the cohomology of the group consisting of all C ∞ -diffeomorphisms of the line, which are C 1 -flat to the identity at the origin. We construct non-trivial two second real cohomology classes and uncountably many second integral homology classes of this group.