Browsing Artículos (Álgebra) by Title
Now showing items 2645 of 210

Classification of subgroups of symplectic groups over finite fields containing a transvection [Article]
(De Gruyter Open, 201606)In this note, we give a selfcontained proof of the following classification (up to conjugation) of finite subgroups of GSpnpF`q containing a nontrivial transvection for ≥ 5, which can be derived from work of Kantor: G ...

Closures of positive braids and the MortonFranksWilliams inequality [Article]
(Elsevier, 20140901)We study the MortonFranksWilliams inequality for closures of simple braids (also known as positive permutation braids). This allows to prove, in a simple way, that the set of simple braids is a orthonormal basis for the ...

Coefficient fields and scalar extension in positive characteristic [Article]
(Elsevier, 20050315)Let k be a perfect field of positive characteristic, k(t)per the perfect closure of k(t) and A = k[[X1, . . . , Xn]]. We show that for any maximal ideal n of A′ = k(t)per ⊗k A, the elements in Ac′ n which are annihilated ...

Cohomologie évanescente padique: calculs locaux [Article]
(Università di Padova, 2000) 
Combinatorics of syzygies for semigroup algebras [Article]
(Universitat de Barcelona, 1998)We describe how the graded minimal resolution of certain semigroup algebras is related to the combinatorics of some simplicial complexes. We obtain characterizations of the CohenMacaulay and Gorenstein conditions. The ...

Combinatorics on a family of reduced Kronecker coefficients [Article]
(Elsevier, 201510)The reduced Kronecker coefficients are particular instances of Kronecker coefficients that contain enough information to recover them. In this notes we compute the generating function of a family of reduced Kronecker ...

Commutation and normal ordering for operators on symmetric functions [Article]
(2015)We study the commutation relations and normal ordering between families of operators on symmetric functions. These operators can be naturally defined by the operations of multiplication, Kronecker product, and their ...

Comparison of theoretical complexities of two methods for computing annihilating ideals of polynomials [Article]
(2005)Let f1, . . . , fp be polynomials in C[x1, . . . , xn] and let D = Dn be the nth Weyl algebra. We provide upper bounds for the complexity of computing the annihilating ideal of f s = f s1 1 · · · f sp p in D[s] = D[s1, . ...

Compatible systems of symplectic Galois representations and the inverse Galois problem I. Images of projective representations [Article]
(American Mathematical Society, 201702)This article is the first part of a series of three articles about compatible systems of symplectic Galois representations and applications to the inverse Galois problem. In this first part, we determine the smallest field ...

Compatible systems of symplectic Galois representations and the inverse Galois problem II. Transvections and huge image [Article]
(Mathematical Sciences Publishers, 201603)This article is the second part of a series of three articles about compatible systems of symplectic Galois representations and applications to the inverse Galois problem. This part is concerned with symplectic Galois ...

Compatible systems of symplectic Galois representations and the inverse Galois problem III. Automorphic construction of compatible systems with suitable local properties [Article]
(Springer, 201504)This article is the third and last part of a series of three articles about compatible systems of symplectic Galois representations and applications to the inverse Galois problem. This part proves the following new result ...

Computation of centralizers in braid groups and Garside groups [Article]
(Consejo Superior de Investigaciones Científicas, 2003)We give a new method to compute the centralizer of an element in Artin braid groups and, more generally, in Garside groups. This method, together with the solution of the conjugacy problem given by the authors in [9] ...

Computational methods in algebra and analysis [Article]
(Sociedad Española de Matemática Aplicada, 200709)This paper describes some applications of Computer Algebra to Algebraic Analysis also known as Dmodule theory, i.e. the algebraic study of the systems of linear partial differential equations. Gröbner bases for rings ...

Computing the rational torsion of an elliptic curve using Tate normal form [Article]
(Elsevier, 200209)It is a classical result (apparently due to Tate) that all elliptic curves with a torsion point of order n (4 ≤ n ≤ 10, or n = 12) lie in a oneparameter family. However, this fact does not appear to have been used ever for ...

Conjugacy in Garside groups I: Cyclings, powers, and rigidity [Article]
(European Mathematical Society, 2007)In this paper a relation between iterated cyclings and iterated powers of elements in a Garside group is shown. This yields a characterization of elements in a Garside group having a rigid power, where ‘rigid’ means that ...

Conjugacy in Garside groups II: Structure of the ultra summit set [Article]
(European Mathematical Society, 2008)This paper is the second in a series in which the authors study the conjugacy decision problem (CDP) and the conjugacy search problem (CSP) in Garside groups. The ultra summit set USS(X) of an element X in a Garside group ...

Conjugacy in Garside Groups III: Periodic braids [Article]
(Elsevier, 20071015)An element in Artin’s braid group Bn is said to be periodic if some power of it lies in the center of Bn. In this paper we prove that all previously known algorithms for solving the conjugacy search problem in Bn are ...

Conjugacy problem for braid groups and Garside groups [Article]
(Elsevier, 20030801)We present a new algorithm to solve the conjugacy problem in Artin braid groups, which is faster than the one presented by Birman, Ko and Lee. This algorithm can be applied not only to braid groups, but to all Garside ...

Conservation of the noetherianity by perfect transcendental field extensions [Article]
(European Mathematical Society, 2003)Let k be a perfect field of characteristic p>0, k(t)per the perfect closure of k(t) and A a kalgebra. We characterize whether the ring A⊗kk(t)per is noetherian when A is the ring of formal power series in n indeterminates over k.

Constructions in R[x_1, ..., x_n]. Applications to KTheory [Article]
(20020625)A classical result in KTheory about polynomial rings like the QuillenSuslin theorem admits an algorithmic approach when the ring of coefficients has some computational properties, associated with Gröbner bases. There ...