Cohomology of modules in the principal block of a finite group.
Modules with injective cohomology, and local duality for a finite group.
Rapport de mission
Conway's Group CO3 and the Dickson Invariants.
Growth Series of Finite Extensions of ...n are Rational.
Multilinearity of sketches.
Le développement du contrôle de la qualité dans les industries américaines
III. Application d'une méthode statistique pour la réception des plaques de blindage
The inverse semigroup of a sumordered semiring.
Commensurations of Out
Let Out(F) denote the outer automorphism group of the free group F with >3. We prove that for any finite index subgroup Γ<Out(F), the group Aut(Γ) is isomorphic to the normalizer of Γ in Out(F). We prove that Γ is : every injective homomorphism Γ→Γ is surjective. Finally, we prove that the abstract commensurator Comm(Out(F)) is isomorphic to Out(F).
Séries de compositions de modules instables et injectivité de la cohomologie du groupe Z/2.
Convex cocompact subgroups of mapping class groups.
Phantom maps and purity in modular representation theory, I
Let k be a field and G a finite group. By analogy with the theory of phantom maps in topology, a map f : M → ℕ between kG-modules is said to be phantom if its restriction to every finitely generated submodule of M factors through a projective module. We investigate the relationships between the theory of phantom maps, the algebraic theory of purity, and Rickard's idempotent modules. In general, adding one to the pure global dimension of kG gives an upper bound for the number of phantoms we need...
Moment sets and the unitary dual of a nilpotent Lie group.
Semilinear Automorphisms and Dimension Functions for Certain Characters of Finite Chevalley Groups.
Equivalences between isolated hypersurface singularities.
Complexity and Multiple Complexes.
Thick subcategories of the stable module category
We study the thick subcategories of the stable category of finitely generated modules for the principal block of the group algebra of a finite group G over a field of characteristic p. In case G is a p-group we obtain a complete classification of the thick subcategories. The same classification works whenever the nucleus of the cohomology variety is zero. In case the nucleus is nonzero, we describe some examples which lead us to believe that there are always infinitely many thick subcategories concentrated...
Invariant theory for the orthogonal group via star products.
Spectra for Gelfand pairs associated with the Heisenberg group
Let K be a closed Lie subgroup of the unitary group U(n) acting by automorphisms on the (2n+1)-dimensional Heisenberg group . We say that is a Gelfand pair when the set of integrable K-invariant functions on is an abelian convolution algebra. In this case, the Gelfand space (or spectrum) for can be identified with the set of bounded K-spherical functions on . In this paper, we study the natural topology on given by uniform convergence on compact subsets in . We show that is a complete...
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