Abstract:
The paper discusses an applicability condition of a cutoff regularization to a fundamental solution of the Laplace operator in the coordinate representation in the Euclidean space of dimension greater than two. To regularize, we consider a deformation of the solution in a sufficiently small ball centered at the origin by cutting off a singular component, and further supplementing it with a continuous function. It is shown that a set of functions satisfying the applicability condition is not empty. As an example, a family of functions is constructed that can be represented by applying a set of averaging operators to the non-regularized solution, and some specific examples are given. Additionally, it is demonstrated that there exist functions that satisfy the condition in a more strict formulation.
Keywords:
cutoff regularization, Green's function, fundamental solution, deformation, coordinate representation.
The work is supported by the Ministry of Science and Higher Education of the Russian Federation, grant 075-15-2022-289, and by the Foundation for the Advancement of Theoretical Physics and Mathematics “BASIS”, grant “Young Russian Mathematics”.
Citation:
Aleksandr Ivanov, “An applicability condition of a cutoff regularization in the coordinate representation”, Funktsional. Anal. i Prilozhen., 59:1 (2025), 5–17; Funct. Anal. Appl., 59:1 (2025), 1–10