Generalized Widder Theorem via fractional moments

TL;DR

This paper establishes a comprehensive criterion for representing functions as multidimensional Laplace transforms with support constraints, extending classical results through advanced moment problem techniques.

Contribution

It introduces a necessary and sufficient condition for multidimensional Laplace transform representation with support restrictions, utilizing a novel application of the Putinar-Vasilescu method.

Findings

Provides a complete characterization of representability conditions.

Extends classical Laplace transform theory to support-constrained measures.

Employs advanced moment problem techniques for multidimensional cases.

Abstract

We provide a necessary and sufficient condition for the representability of a function as the classical multidimensional Laplace transform, when the support of the representing measure is contained in some generalized semi-algebraic set. This is done by employing a method of Putinar and Vasilescu [Putinar, M. and Vasilescu, F.-H., Solving moment problems by dimensional extension, Ann. of Math. (2) 149 (1999), no. 3, 1087-1107] for the corresponding multidimensional moment problem.