A Disproof of a Conjecture of Robertson and Generalizations
A function related to a Lagrange-Bürmann series
An infinite series which arises in certain applications of the Lagrange-Bürmann formula to exponential functions is investigated. Several very exact estimates for the Laplace transform and higher moments of this function are developed.
A lower bound on the radius of analyticity of a power series in a real Banach space
Let F be a power series centered at the origin in a real Banach space with radius of uniform convergence ϱ. We show that F is analytic in the open ball B of radius ϱ/√e, and furthermore, the Taylor series of F about any point a ∈ B converges uniformly within every closed ball centered at a contained in B.
A note on matrix transformations of holomorphic Dirichlet series.
A pointwise growth estimate for analytic functions in tubes.
A Vanishing Theorem for Power Series.
Accelero-summation of the formal solutions of nonlinear difference equations
In 1996, Braaksma and Faber established the multi-summability, on suitable multi-intervals, of formal power series solutions of locally analytic, nonlinear difference equations, in the absence of “level ”. Combining their approach, which is based on the study of corresponding convolution equations, with recent results on the existence of flat (quasi-function) solutions in a particular type of domains, we prove that, under very general conditions, the formal solution is accelero-summable. Its sum...
An elementary proof of the Briançon-Skoda theorem
We give an elementary proof of the Briançon-Skoda theorem. The theorem gives a criterionfor when a function belongs to an ideal of the ring of germs of analytic functions at ; more precisely, the ideal membership is obtained if a function associated with and is locally square integrable. If can be generated by elements,it follows in particular that , where denotes the integral closure of an ideal .
An expansion theorem for nonanalytic functions in several complex variables.
Approximation de fonctions holomorphes d'un nombre infini de variables
Soit un espace de Banach complexe, et notons la boule de rayon centrée en . On considère le problème d’approximation suivant: étant donnés , et une fonction holomorphe dans , existe-t-il toujours une fonction , holomorphe dans , telle que sur ? On démontre que c’est bien le cas si est l’espace des suites sommables.
Approximation of entire functions of two complex variables in Banach spaces.
Approximation of holomorphic functions of infinitely many variables II
Let be a Banach space and the ball of radius centered at . Can any holomorphic function on be approximated by entire functions, uniformly on smaller balls ? We answer this question in the affirmative for a large class of Banach spaces.
Automorphismes analytiques des produits continus de domaines bornés