Search results for "F36"
showing 10 items of 38 documents
Artin groups of spherical type up to isomorphism
2003
AbstractWe prove that two Artin groups of spherical type are isomorphic if and only if their defining Coxeter graphs are the same.
The proof of Birman’s conjecture on singular braid monoids
2003
Let B_n be the Artin braid group on n strings with standard generators sigma_1, ..., sigma_{n-1}, and let SB_n be the singular braid monoid with generators sigma_1^{+-1}, ..., sigma_{n-1}^{+-1}, tau_1, ..., tau_{n-1}. The desingularization map is the multiplicative homomorphism eta: SB_n --> Z[B_n] defined by eta(sigma_i^{+-1}) =_i^{+-1} and eta(tau_i) = sigma_i - sigma_i^{-1}, for 1 <= i <= n-1. The purpose of the present paper is to prove Birman's conjecture, namely, that the desingularization map eta is injective.
Integration of Capital Markets from Central and Eastern Europe: Implications for EU Investors
2014
Our paper investigates the extent of capital market co-movements between three emerging markets– Czech Republic, Hungary and Poland – and three developed markets from the European Union - Austria, France and Germany. We test whether an increase in correlations between the six markets took place in recent years, as revealing higher integration of capital markets in the region. We find a statistically significant positive trend in cross-market correlations between 1999 and 2008, before the emergence of the global financial crisis. Movements in national stock markets are not fully synchronized, but increases in market volatilities lead to increases in cross-country correlations. There is a lon…
Artin monoids inject in their groups
2001
We prove that the natural homomorphism from an Artin monoid to its associated Artin group is always injective
From braid groups to mapping class groups
2005
This paper is a survey of some properties of the braid groups and related groups that lead to questions on mapping class groups.
Vassiliev invariants for braids on surfaces
2000
We show that Vassiliev invariants separate braids on a closed oriented surface, and we exhibit an universal Vassiliev invariant for these braids in terms of chord diagrams labeled by elements of the fundamental group of the considered surface.
Categorical action of the extended braid group of affine type $A$
2017
Using a quiver algebra of a cyclic quiver, we construct a faithful categorical action of the extended braid group of affine type A on its bounded homotopy category of finitely generated projective modules. The algebra is trigraded and we identify the trigraded dimensions of the space of morphisms of this category with intersection numbers coming from the topological origin of the group.
Geometric représentations of the braid groups
2010
We show that the morphisms from the braid group with n strands in the mapping class group of a surface with a possible non empty boundary, assuming that its genus is smaller or equal to n/2 are either cyclic morphisms (their images are cyclic groups), or transvections of monodromy morphisms (up to multiplication by an element in the centralizer of the image, the image of a standard generator of the braid group is a Dehn twist, and the images of two consecutive standard generators are two Dehn twists along two curves intersecting in one point). As a corollary, we determine the endomorphisms, the injective endomorphisms, the automorphisms and the outer automorphism group of the following grou…
50 years of capital mobility in the eurozone: breaking the Feldstein-Horioka puzzle
2021
AbstractThis paper assesses capital mobility for the Eurozone countries by studying the long-run relationship between domestic investment and savings for the period 1970-2019. Our main goal is to analyze the impact of economic events on capital mobility during this period. We apply the cointegration methodology in a setting that allows us to identify endogenous breaks in the long-run saving-investment relationship. Precisely, the breaks coincide with relevant economic events. We find a downward trend in the saving-investment retention since the 70s for the so-called “core countries”, whereas this trend is not so evident in the peripheral, where the financial and sovereign crises have had a …
Les tresses : de la topologie à la cryptographie
2009
International audience; Ce texte est une présentation sur les groupes de tresses destinée à un public de non mathématiciens.