Some examples for the Poincaré and Painlevé problems
Some Examples of Rigid Representations
*Research partially supported by INTAS grant 97-1644.Consider the Deligne-Simpson problem: give necessary and sufficient conditions for the choice of the conjugacy classes Cj ⊂ GL(n,C) (resp. cj ⊂ gl(n,C)) so that there exist irreducible (p+1)-tuples of matrices Mj ∈ Cj (resp. Aj ∈ cj) satisfying the equality M1 . . .Mp+1 = I (resp. A1+. . .+Ap+1 = 0). The matrices Mj and Aj are interpreted as monodromy operators and as matrices-residua of fuchsian systems on Riemann’s sphere. We give new examples...
Some precise estimates of the hyper order of solutions of some complex linear differential equations.
Some Results on Hypertranscendental Meromorphic Functions.
Some results on the complex oscillation theory of differential equations with polynomial coefficients.
Some results on the complex oscillation theory of some differential polynomials.
Some Results on the Properties of Differential Polynomials Generated by Solutionsof Complex Differential Equations
This paper is devoted to considering the complex oscillation of differential polynomials generated by meromorphic solutions of the differential equation where
Sommation effective d’une somme de Borel par séries de factorielles
Nous abordons dans cet article la question de la sommation effective d’une somme de Borel d’une série par la série de factorielles associée. Notre approche fournit un contrôle de l’erreur entre la somme de Borel recherchée et les sommes partielles de la série de factorielles. Nous généralisons ensuite cette méthode au cadre des séries de puissances fractionnaires, après avoir démontré un analogue d’un théorème de Nevanlinna de sommation de Borel fine pour ce cadre.
Stokes matrices of hypergeometric integrals
In this work we compute the Stokes matrices of the ordinary differential equation satisfied by the hypergeometric integrals associated to an arrangement of hyperplanes in generic position. This generalizes the computation done by J.-P. Ramis for confluent hypergeometric functions, which correspond to the arrangement of two points on the line. The proof is based on an explicit description of a base of canonical solutions as integrals on the cones of the arrangement, and combinatorial relations between...
Stokes multipliers for subdominant solutions of second order differential equations with polynomial coefficients.
Stokes phenomenon, multisummability and differential Galois groups
We precise the cohomological analysis of the Stokes phenomenon for linear differential systems due to Malgrange and Sibuya by making a rigid natural choice of a unique cocycle (called a Stokes cocyle) in every cohomological class. And we detail an algebraic algorithm to reduce any cocycle to its cohomologous Stokes form. This gives rise to an almost algebraic definition of sums for formal solutions of systems which we compare to the most usual ones. We also use this construction to the Stokes cocycle...
Subnormal solutions of second-order nonhomogeneous linear differential equations with periodic coefficients.
Summability of first integrals of a -non-integrable resonant Hamiltonian system
This article studies the summability of first integrals of a -non-integrable resonant Hamiltonian system. The first integrals are expressed in terms of formal exponential transseries and their Borel sums. Smooth Liouville integrability and a relation to the Birkhoff transformation are discussed from the point of view of the summability.
Summation of Formal Power Series Through Iterated Laplace Integrals.
Supersymmetric quantum mechanics and Painlevé IV equation.
Supersymmetry transformations for delta potentials.
Sur certaines solutions particulières transcendantes des équations d'Einstein
Sur la forme des intégrales des équations différentielles du premier ordre dans le voisinage de certains points critiques
Sur le méthode de l'intégrale généralisée de Laplace appliquée aux équations aréolaires linéaires
Sur les équations différentielles algébriques admettant des solutions avec une singularité essentielle
On démontre qu'une feuille transcendante d'un feuilletage analytique sur une surface fibrée doit intersecter toute courbe algébrique non invariante et non contenue dans une réunion de fibres de la fibration; comme application on montre qu'une équation différentielle algébrique qui possède une solution locale avec une singularité essentielle n'a pas de ramification mobile, ce qui généralise les théorèmes de Malmquist et Yosida.