Esenin-Volpin's theorem

Esenin-Volpin's theorem is a result in the field of mathematics, specifically in the area of functional analysis and the theory of distributions. The theorem deals with the relationship between certain types of linear functionals and their representations through measures. The essence of Esenin-Volpin's theorem is that it provides conditions under which a linear functional acting on a space of test functions can be uniquely represented as an integral with respect to a measure.