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Calculations about multiplicities.

Manuel Abellanas (1982)

Revista Matemática Hispanoamericana

One gives a formula for the calculation of the local intersection multiplicity index of analytic varieties, analogous to the Bézout formula in the case of algebraic varieties in the projective space, in the case of normal crossings. One obtains also a recurrent process for the calculation of the local intersection multiplicity index of plane analytic curves.

Calculs d'invariants primitifs de groupes finis

Ines Abdeljaouad (2010)

RAIRO - Theoretical Informatics and Applications

We introduce in this article a new method to calculate all absolute and relatif primitive invariants of finite groups. This method is inspired from K. Girstmair which calculate an absolute primitive invariant of minimal degree. Are presented two algorithms, the first one enable us to calculate all primitive invariants of minimal degree, and the second one calculate all absolute or relative primitive invariants with distincts coefficients. This work take place in Galois Theory and Invariant Theory. ...

Cale Bases in Algebraic Orders

Martine Picavet-L’Hermitte (2003)

Annales mathématiques Blaise Pascal

Let R be a non-maximal order in a finite algebraic number field with integral closure R ¯ . Although R is not a unique factorization domain, we obtain a positive integer N and a family 𝒬 (called a Cale basis) of primary irreducible elements of R such that x N has a unique factorization into elements of 𝒬 for each x R coprime with the conductor of R . Moreover, this property holds for each nonzero x R when the natural map Spec ( R ¯ ) Spec ( R ) is bijective. This last condition is actually equivalent to several properties linked...

Cambrian fans

Nathan Reading, David E. Speyer (2009)

Journal of the European Mathematical Society

For a finite Coxeter group W and a Coxeter element c of W ; the c -Cambrian fan is a coarsening of the fan defined by the reflecting hyperplanes of W . Its maximal cones are naturally indexed by the c -sortable elements of W . The main result of this paper is that the known bijection cl c between c -sortable elements and c -clusters induces a combinatorial isomorphism of fans. In particular, the c -Cambrian fan is combinatorially isomorphic to the normal fan of the generalized associahedron for W . The rays...

Caractères numériques et fonctions de Macaulay.

Mireille Martin-Deschamps (2004)

Collectanea Mathematica

The postulation of Aritméticamente Cohen-Macaulay (ACM) subschemes of the projective space PkN is well known in the case of codimension 2. There are many different ways of recording this numerical information: numerical character of Gruson/Peskine, h-vector, postulation character of Martin-Deschamps/Perrin... The first aim of this paper is to show the equivalence of these notions. The second and most important aim, is to study the postulation of codimension 3 ACM subschemes of PN. We use a result...

Castelnuovo-Mumford regularity of products of ideals.

Aldo Conca, Jürgen Herzog (2003)

Collectanea Mathematica

The Castelnuovo-Mumford regularity reg(M) is one of the most important invariants of a finitely generated graded module M over a polynomial ring R. For instance, it measures the amount of computational resources that working with M requires. In general one knows that the regularity of a module can be doubly exponential in the degrees of the minimal generators and in the number of the variables. On the other hand, in many situations one has or one conjectures a much better behavior. One may ask,...

Categorification of the virtual braid groups

Anne-Laure Thiel (2011)

Annales mathématiques Blaise Pascal

We extend Rouquier’s categorification of the braid groups by complexes of Soergel bimodules to the virtual braid groups.

Cellular covers of cotorsion-free modules

Rüdiger Göbel, José L. Rodríguez, Lutz Strüngmann (2012)

Fundamenta Mathematicae

In this paper we improve recent results dealing with cellular covers of R-modules. Cellular covers (sometimes called colocalizations) come up in the context of homotopical localization of topological spaces. They are related to idempotent cotriples, idempotent comonads or coreflectors in category theory. Recall that a homomorphism of R-modules π: G → H is called a cellular cover over H if π induces an isomorphism π : H o m R ( G , G ) H o m R ( G , H ) , where π⁎(φ) = πφ for each φ H o m R ( G , G ) (where maps are acting on the left). On the one hand,...

Currently displaying 421 – 440 of 2826