Page 1 Next

Displaying 1 – 20 of 24

Showing per page

Congruences between Siegel modular forms on the level of group cohomology

Karsten Buecker (1996)

Annales de l'institut Fourier

Vector-valued Siegel modular forms may be found in certain cohomology groups with coefficients lying in an irreducible representation of the symplectic group. Using functoriality in the coefficients, we show that the ordinary components of the cohomology are independent of the weight parameter. The meaning of ordinary depends on a choice of parabolic subgroup of G S p ( 4 ) , giving a particular direction in the change of weight. Our results complement those of Taylor and Tilouine-Urban for the two other possible...

Foncteurs de division et structure de I 2 Λ n dans la catégorie

Aurélien Djament (2007)

Annales de l’institut Fourier

Nous démontrons que dans la catégorie des foncteurs entre espaces vectoriels sur 𝔽 2 , le produit tensoriel entre le second foncteur injectif standard non constant V 𝔽 2 ( V * ) 2 et un foncteur puissance extérieure est artinien. Seul était antérieurement connu le caractère artinien de cet injectif ; notre résultat constitue une étape pour l’étude du troisième foncteur injectif standard non constant de  .Nous utilisons le foncteur de division par le foncteur identité et des considérations issues de la théorie...

Generic representations of orthogonal groups: projective functors in the category q u a d

Christine Vespa (2008)

Fundamenta Mathematicae

We continue the study of the category of functors q u a d , associated to ₂-vector spaces equipped with a nondegenerate quadratic form, initiated in J. Pure Appl. Algebra 212 (2008) and Algebr. Geom. Topology 7 (2007). We define a filtration of the standard projective objects in q u a d ; this refines to give a decomposition into indecomposable factors of the first two standard projective objects in q u a d : P H and P H . As an application of these two decompositions, we give a complete description of the polynomial functors...

Reedy categories which encode the notion of category actions

Julia E. Bergner, Philip Hackney (2015)

Fundamenta Mathematicae

We study a certain type of action of categories on categories and on operads. Using the structure of the categories Δ and Ω governing category and operad structures, respectively, we define categories which instead encode the structure of a category acting on a category, or a category acting on an operad. We prove that the former has the structure of an elegant Reedy category, whereas the latter has the structure of a generalized Reedy category. In particular, this approach gives a new way to regard...

Currently displaying 1 – 20 of 24

Page 1 Next