Now showing items 122-141 of 209

• #### New presentations of surface braid groups ﻿ [Article]

(World Scientific Publishing, 2001)
In this paper we give new presentations of the braid groups and the pure braid groups of a closed surface. We also give an algorithm to solve the word problem in these groups, using the given presentations.
• #### Nouvelle Cuisine for the Computation of the Annihilating Ideal of $f^s$ ﻿ [Chapter of Book]

(2005)
Let $f_1,\ldots, f_p$ be polynomials in ${\bf C}[x_1,\ldots, x_n]$ and let $D = D_n$ be the $n$-th Weyl algebra. The annihilating ideal of $f^s=f_1^{s_1}\cdots f_p^{s_p}$ in $D[s]=D[s_1,\ldots,s_p]$ is a necessary step ...
• #### Los números de (Euler)-Catalan ﻿ [Article]

(Asociación Matemática Venezolana, 2003)
• #### On a conjecture by Kauffman on alternative and pseudoalternating links ﻿ [Article]

(Elsevier, 2015-06)
It is known that alternative links are pseudoalternating. In 1983 Louis Kauffman conjectured that both classes are identical. In this paper we prove that Kauffman Conjecture holds for those links whose first Betti number ...
• #### On a determinantal formula of Tadić ﻿ [Article]

(Johns Hopkins University Press, 2014-02)
We study a special class of irreducible representations of GLn over a local non-Archimedean field which we call ladder representations. This is a natural class in the admissible dual which contains the Speh representations. ...
• #### On conjectures of Sato-Tate and Bruinier-Kohnen ﻿ [Article]

(Springer, 2015-04)
This article covers three topics. (1) It establishes links between the density of certain subsets of the set of primes and related subsets of the set of natural numbers. (2) It extends previous results on a conjecture of ...
• #### On determinant functors and K-theory ﻿ [Article]

(Universitat Autònoma de Barcelona, 2015)
We extend Deligne’s notion of determinant functor to Waldhausen categories and (strongly) triangulated categories. We construct explicit universal determinant functors in each case, whose target is an algebraic model for ...
• #### On dilatation factors of braids on three strands ﻿ [Article]

(World Scientific Publishing, 2015-04)
In this work we present a natural surjective map from rigid braids in B3 (in Garside sense) to SL2(N). This map provides an upper and a lower bound for the dilatation factor of a pseudo-Anosov 3-strand braid. These bounds ...
• #### On irregular binomial D-modules ﻿ [Article]

(Springer, 2012-12)
We prove that a holonomic binomial D–module MA(I, β) is regular if and only if certain associated primes of I determined by the parameter vector β ∈ Cd are homogeneous. We further describe the slopes of MA(I, β) along a ...
• #### On reduction curves and Garside properties of braids ﻿ [Article]

(American Mathematical Society, 2011)
In this paper we study the reduction curves of a braid, and how they can be used to decompose the braid into simpler ones in a precise way, which does not correspond exactly to the decomposition given by Thurston theory. ...
• #### On simultaneous arithmetic progressions on elliptic curves ﻿ [Article]

(Taylor & Francis, 2006)
In this paper we study elliptic curves which have a number of points whose coordinates are in arithmetic progression. We first motivate this diophantine problem, prove some results, provide a number of interesting examples ...
• #### On the centralizer of generic braids ﻿ [Article]

(De Gruyter, 2018-11)
We study the centralizer of a braid from the point of view of Garside theory, showing that generically a minimal set of generators can be computed very efficiently, as the ultra summit set of a generic braid has a very ...
• #### On the cycling operation in braid groups ﻿ [Article]

(Elsevier, 2008-09-06)
The cycling operation is a special kind of conjugation that can be applied to elements in Artin’s braid groups, in order to reduce their length. It is a key ingredient of the usual solutions to the conjugacy problem in ...
• #### On the dimension of discrete valuations of k ((X1, ..., Xn)) ﻿ [Article]

(Elsevier, 2001-07-01)
Let v be a rank-one discrete valuation of the field Kn=k((X1,…,Xn)). We know, after [1], that if n=2 then the dimension of v is 1 and if v is the usual order function over k((X1,…,Xn)) its dimension is n−1. In this paper ...
• #### On the functoriality of cohomology of categories ﻿ [Article]

(Elsevier, 2006-03)
In this paper we show that the Baues-Wirsching complex used to define cohomology of categories is a 2-functor from a certain 2-category of natural systems of abelian groups to the 2-category of chain complexes, chain ...
• #### On the logarithmic comparison theorem for integrable logarithmic connections ﻿ [Article]

(London Mathematical Society, 2009)
Let X be a complex analytic manifold, D ⊂ X a free divisor with jacobian ideal of linear type (e.g. a locally quasi-homogeneous free divisor), j : U = X − D ֒→ X the corresponding open inclusion, E an integrable logarithmic ...
• #### On the modules of m-integrable derivations in non-zero characteristic ﻿ [Article]

(Elsevier, 2012-03-20)
Let k be a commutative ring and A a commutative k-algebra. Given a positive integer m, or m = ∞, we say that a k-linear derivation δ of A is m-integrable if it extends up to a Hasse–Schmidt derivation D = (Id, D1 = δ, ...
• #### On the number of rational points on curves over finite fields with many automorphisms ﻿ [Article]

(Elsevier, 2013-01)
Using Weil descent, we give bounds for the number of rational points on two families of curves over finite fields with a large abelian group of automorphisms: Artin–Schreier curves of the form yq−y=f(x) with f∈Fqr[x], on ...
• #### On the singular braid monoid of an orientable surface ﻿ [Article]

(American Mathematical Society, 2004)
In this paper we show that the singular braid monoid of an orientable surface can be embedded in a group. The proof is purely topological, making no use of the monoid presentation.
• #### On the Sn-module structure of the noncommutative harmonics ﻿ [Article]

(Elsevier, 2008-08)
Using the a noncommutative version of Chevalley’s theorem due to Bergeron, Reutenauer, Rosas, and Zabrocki we compute the graded Frobenius series for their two sets of noncommutative harmonics with respect to the left ...