20 citations · 86 across the 50 of their papers we have counts for
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On parametric -Gevrey asymptotic expansions in two levels for some linear partial -difference-differential equations
Alberto Lastra, Stephane Malek
A novel asymptotic representation of the analytic solutions to a family of singularly perturbed difference-differential equations in the complex domain is obtained. Such asympt…
On a moment generalization of some classical second-order differential equations generating classical orthogonal polynomials
Edmundo J. Huertas, Alberto Lastra, Víctor Soto-Larrosa
The aim of the work is to construct new polynomial systems, which are solutions to certain functional equations which generalize the second-order differential equations satisfied b…
Solutions of linear systems of moment differential equations via generalized matrix exponentials
Alberto Lastra, Cruz Prisuelos-Arribas
A generalized exponential matrix based on the construction of kernel operators for generalized summability is defined and analyzing its main properties, generalizing the classical…
Small divisors in the problem of the convergence of generalized power series solutions of -difference equations
Renat Gontsov, Irina Goryuchkina, Alberto Lastra
The question of the convergence of generalized formal power series (with complex power exponents) solutions of -difference equations is studied in the situation where the small…
Higher-order recurrence relations, Sobolev-type inner products and matrix factorizations
Carlos Hermoso, Edmundo J. Huertas, Alberto Lastra +1
It is well known that Sobolev-type orthogonal polynomials with respect to measures supported on the real line satisfy higher-order recurrence relations and these can be expressed a…
Multisummability of formal solutions for a family of generalized singularly perturbed moment differential equations
Alberto Lastra, Sławomir Michalik, Maria Suwińska
The notion of moment differentiation is extended to the set of generalized multisums of formal power series via an appropriate integral representation and accurate estimates of the…
Entire solutions of linear systems of moment differential equations and related asymptotic growth at infinity
Alberto Lastra
The general entire solution to a linear system of moment differential equations is obtained in terms of a moment kernel function for generalized summability, and the Jordan decompo…
On second order q-difference equations for high-order Sobolev-type q-Hermite orthogonal polynomials
Carlos Hermoso, Edmundo J. Huertas, Alberto Lastra +1
The q-Hermite I-Sobolev type polynomials of higher order are consider for their study. Their hypergeometric representation is provided together with further useful properties such…
On the convergence of generalized power series solutions of -difference equations
Renat Gontsov, Irina Goryuchkina, Alberto Lastra
A sufficient condition for the convergence of a generalized formal power series solution to an algebraic -difference equation is provided. The main result leans on a geometric p…
On second order q-difference equations satisfied by Al-Salam-Carlitz I-Sobolev type polynomials of higher order
Carlos Hermoso, Edmundo J. Huertas, Alberto Lastra +1
This contribution deals with the sequence of monic polynomials, orthogonal with respect to a Sobolev-type inner product related to the A…
On the multiple-scale analysis for some linear partial -difference and differential equations with holomorphic coefficients
Thomas Dreyfus, Alberto Lastra, Stéphane Malek
The analytic and formal solutions of certain family of -difference-differential equations under the action of a complex perturbation parameter is considered. The previous study…
On q-asymptotics for linear q-difference-differential equations with Fuchsian and irregular singularities
Alberto Lastra, Stephane Malek, Javier Sanz
We consider a Cauchy problem for some family of q-difference-differential equations with Fuchsian and irregular singularities, that admit a unique formal power series solution in t…