1 citations · 2 across the 9 of their papers we have counts for
9 papers
On the product of two generic -Gevrey series
Thomas Dreyfus, Changgui Zhang
In this paper, we consider a -analog of the Borel-Laplace summation process introduced by Fabienne Marotte and the second author. We specifically examine two power series soluti…
On the positive powers of -analogs of Euler series
Changgui Zhang
The most simple and famous divergent power series coming from ODE may be the so-called Euler series , that, as well as all its positive powers, is…
On the vanishing of coefficients of the powers of a theta function
Jacques Sauloy, Changgui Zhang
A result on the Galois theory of -difference equations \cite{JSTALPAEN} leads to the following question: if $q \in \Cs$, $\lmod q \rmod < 1$ and if one sets $\thq(z) := \sum\lim…
Analytic continuation of solutions of the pantograph equation by means of -modular formula
Changgui Zhang
The aim of this paper is to treat the constant coefficients functional-differential equation with the help of the analytic theory of linear -difference equa…
On a family of symmetric hypergeometric functions of several variables and their Euler type integral representation
Zhuangchu Luo, Hua Chen, Changgui Zhang
This paper is devoted to the family of hypergeometric series of any finite number of variables, the coefficients being the square of the multinomial coefficients $(\ell_1…
On the Modular Behaviour of the Infinite Product
Changgui Zhang
Let , , $x=e^{2πiξ}\in\CC$ and . Let be the classical modular substitution given by $q^*=e^{-2πi/…
Exponential type Nagumo norms and summability of formal solutions of singular partial differential equations
Zhuangchu Luo, Hua Chen, Changgui Zhang
In this paper, we study a class of first order nonlinear degenerated partial differential equations with singularity at $(t,x)=(0,0)\in \CC^2$. By means of exponential type Nagumo…
La série entière possède une frontière naturelle~!
Changgui Zhang
The lacunary series are the most classical examples among all the power series whose circle of convergence constitutes a natural boundary (\cite[§~93-94, p.~372-383]{Di}, \cite[§7.…
A modular type formula for Euler infinite product
Changgui Zhang
The main goal of this paper is to give a modular type representation for the infinite product . It is shown that this representation essentially con…