Displaying 341 – 360 of 484

Showing per page

Solutions entières d'un système d'équations aux différences. II

Jean-Paul Bézivin, François Gramain (1996)

Annales de l'institut Fourier

Soit s un entier naturel non nul, et f une fonction entière de s variables complexes. Dans un article précédent, nous avons démontré dans le cas s = 1 , que si f est une solution d’un système de 2 équations aux différences à coefficients polynomiaux dans deux directions différentes, avec une condition restrictive portant sur les équations, alors f est le quotient d’un polynôme exponentiel par un polynôme. Dans cet article, nous démontrons ce résultat dans le cas général, et l’analogue pour le cas de...

Solutions of non-homogeneous linear differential equations in the unit disc

Ting-Bin Cao, Zhong-Shu Deng (2010)

Annales Polonici Mathematici

The main purpose of this paper is to consider the analytic solutions of the non-homogeneous linear differential equation f ( k ) + a k - 1 ( z ) f ( k - 1 ) + + a ( z ) f ' + a ( z ) f = F ( z ) , where all coefficients a , a , . . . , a k - 1 , F ≢ 0 are analytic functions in the unit disc = z∈ℂ: |z|<1. We obtain some results classifying the growth of finite iterated order solutions in terms of the coefficients with finite iterated type. The convergence exponents of zeros and fixed points of solutions are also investigated.

Some addition to the generalized Riemann-Hilbert problem

R.R. Gontsov, I.V. Vyugin (2009)

Annales de la faculté des sciences de Toulouse Mathématiques

We consider the generalized Riemann-Hilbert problem for linear differential equations with irregular singularities. If one weakens the conditions by allowing one of the Poincaré ranks to be non-minimal, the problem is known to have a solution. In this article we give a bound for the possibly non-minimal Poincaré rank. We also give a bound for the number of apparent singularities of a scalar equation with prescribed generalized monodromy data.

Some Examples of Rigid Representations

Kostov, Vladimir (2000)

Serdica Mathematical Journal

*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 Results on the Properties of Differential Polynomials Generated by Solutionsof Complex Differential Equations

Zinelâabidine LATREUCH, Benharrat BELAÏDI (2015)

Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica

This paper is devoted to considering the complex oscillation of differential polynomials generated by meromorphic solutions of the differential equation f ( k ) + A k - 1 ( z ) f ( k - 1 ) + + A 1 ( z ) f ' + A 0 ( z ) f = 0 , where A i ( z ) ( i = 0 , 1 ...

Sommation effective d’une somme de Borel par séries de factorielles

Eric Delabaere, Jean-Marc Rasoamanana (2007)

Annales de l’institut Fourier

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

Alexey Glutsyuk, Christophe Sabot (2010)

Annales de l’institut Fourier

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...

Currently displaying 341 – 360 of 484