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A variational problem for couples of functions andmultifunctions with interaction between leaves

Published online by Cambridge University Press:  16 January 2012

Emilio Acerbi
Affiliation:
Dipartimento di Matematica dell’Università di Parma, Parco Area delle Scienze 53/A, 43124 Parma, Italy. [email protected]; [email protected]; [email protected]
Gianluca Crippa
Affiliation:
Dipartimento di Matematica dell’Università di Parma, Parco Area delle Scienze 53/A, 43124 Parma, Italy. [email protected]; [email protected]; [email protected]
Domenico Mucci
Affiliation:
Dipartimento di Matematica dell’Università di Parma, Parco Area delle Scienze 53/A, 43124 Parma, Italy. [email protected]; [email protected]; [email protected]
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Abstract

We discuss a variational problem defined on couples of functions that are constrained totake values into the 2-dimensional unit sphere. The energy functional contains, besidesstandard Dirichlet energies, a non-local interaction term that depends on the distancebetween the gradients of the two functions. Different gradients are preferred or penalizedin this model, in dependence of the sign of the interaction term. In this paper we studythe lower semicontinuity and the coercivity of the energy and we find an explicitrepresentation formula for the relaxed energy. Moreover, we discuss the behavior of theenergy in the case when we consider multifunctions with two leaves rather than couples offunctions.

Type
Research Article
Copyright
© EDP Sciences, SMAI, 2012

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