Young functions on varifolds. Part I. Functional analytic foundations

Abstract: In this paper, we study Young functions, a measure-theoretic model for multiple-valued functions, and the convergence of pairs of measures and Young functions via their associated graph measures. This setting allows us to study the convergence of pairs of surfaces and functions thereon, and a compactness theorem is immediate. To develop notions of differentiability of Young functions in the upcoming papers, we also introduce and investigate several test function spaces.