Relaxation of a scalar nonlocal variational problem with a double-well potential

We consider nonlocal variational problems in Lp, like those that appear in peridynamics, where the functional object of the study is given by a double integral. It is known that convexity of the integrand implies the lower semicontinuity of the functional in the weak topology of Lp. If the integrand...

Full description

Bibliographic Details
Authors: Mora Corral, Carlos, Tellini, Andrea
Format: article
Publication Date:2020
Country:España
Institution:Universidad Autónoma de Madrid
Repository:Biblos-e Archivo. Repositorio Institucional de la UAM
Language:English
OAI Identifier:oai:repositorio.uam.es:10486/698560
Online Access:http://hdl.handle.net/10486/698560
https://dx.doi.org/10.1007/s00526-020-1728-4
Access Level:Open access
Keyword:Relaxation
Nonlocal problems
Optimality conditions
Young Measures
Double-well potential
Matemáticas
Description
Summary:We consider nonlocal variational problems in Lp, like those that appear in peridynamics, where the functional object of the study is given by a double integral. It is known that convexity of the integrand implies the lower semicontinuity of the functional in the weak topology of Lp. If the integrand is not convex, a usual approach is to compute the relaxation, which is the lower semicontinuous envelope in the weak topology. In this paper we compute such a relaxation for a scalar problem with a double-well integrand. The relaxation is non-trivial, and, contrary to the local case, it cannot be represented as a double integral, as the original problem. Nonetheless, we show that, as for the local case, the relaxation can be expressed in terms of the energy of a suitable truncation of the considered function