We give a sufficient condition for a hermitian holomorphic vector bundle over the disk to be quasi-isometric to the trivial bundle. One consequence is a version of Cartan's lemma on the factorization of matrices with uniform bounds.

In this paper we study the structure of manifolds that contain a quasi-line and give some evidence towards the fact that the irreducible components of degenerations of the quasi-line should determine the Mori cone. We show that the minimality with respect to a quasi-line yields strong restrictions on fibre space structures of the manifold.

A lattice model with exponential interaction, was proposed and integrated by M. Toda in the 1960s; it was then extensively studied as one of the completely integrable (differential-difference) equations by algebro-geometric methods, which produced both quasi-periodic solutions in terms of theta functions of hyperelliptic curves and periodic solutions defined on suitable Jacobians by the Lax-pair method. In this work, we revisit Toda’s original approach to give solutions of the Toda lattice in terms...

This is a survey (including new results) of relations ?some emergent, others established? among three notions which the 1980s saw introduced into knot theory: quasipositivity of a link, the enhanced Milnor number of a fibered link, and the new link polynomials. The Seifert form fails to determine these invariants; perhaps there exists an ?enhanced Seifert form? which does.

Fix $K$ a $p$-adic field and denote by $G_K$ its absolute Galois group. Let $K_{\infty }$ be the extension of $K$ obtained by adding $p^n$-th roots of a fixed uniformizer, and $G_{\infty }\subset G_K$ its absolute Galois group. In this article, we define a class of $p$-adic torsion representations of $G_{\infty }$, calledquasi-semi-stable. We prove that these representations are “explicitly” described by a certain category of linear algebraic objects. The results of this note should be considered as a first step in the understanding of the structure of quotient...

Building on a recent paper [8], here we argue that the combinatorics of matroids are intimately related to the geometry and topology of toric hyperkähler varieties. We show that just like toric varieties occupy a central role in Stanley’s proof for the necessity of McMullen’s conjecture (or g-inequalities) about the classification of face vectors of simplicial polytopes, the topology of toric hyperkähler varieties leads to new restrictions on face vectors of matroid complexes. Namely in this paper...

Un résultat de positivité de théorie de Hodge nous permet de déterminer certaines pôles de la distribution $|f{|}^{2z}$ pour $f$ une fonction analytique à singularité isolée. Dans le cas des courbes et des singularités quasi-homogènes on détermine l’ensemble exact des pôles. On démontre aussi que si le résidu d’une forme holomorphe est de carré intégrable sur la fibre spéciale, l’intégrale sur la fibre spéciale est limite de celle sur les fibres voisines.

Soit $C$ la courbe projective lisse et irréductible, définie sur $Q$, et dont un modèle affine est donné par $y^2=x^5-1$. On désigne par $\infty$ l’unique point de $C$ qui n’est pas contenu dans cette partie affine. Soit $J$ la jacobienne de $C$ et soit $\phi :C^2⟶J$ le morphisme associant à chaque couple $(\xi ,\eta )$ de points de $C$ la classe du diviseur $\left[\xi \right]+\left[\eta \right]-2\left[\infty \right]$ dans Pic${}_{0}C$. Soient $u,v,f$ les trois fonctions rationnelles sur $J$ définies par$$\begin{array}{cc}\hfill u\circ \phi (\xi ,\eta )& =x\left(\xi \right)+x\left(\eta \right),\hfill \\ \hfill v\circ \phi (\xi ,\eta )& =x\left(\xi \right)x\left(\eta \right),\hfill \\ \hfill f& =-u+v+1\hfill \end{array}$$Le but de cet article est de montrer que pour tout point $P$ de $3$-division non nul de $J,u\left(P\right)$ et $v\left(P\right)$ sont des entiers algébriques...

On étudie différentes propriétés d’approximation pour des espaces homogènes $X$ (à stabilisateur fini) de ${\mathrm{GL}}_n$ sur un corps de nombres. On discute également du lien avec le problème de Galois inverse et on établit une formule pour le groupe de Brauer non ramifié de $X$.