On some nonlinear partial differential equations involving the 1-Laplacian

Abstract

In this paper we present an approximation result concerning the first eigenvalue of the 1-Laplacian operator. More precisely, for $\Omega$ a bounded regular open domain, we consider a minimisation of the functional ${\ds \int_Ω}|\nabla u|+n({\ds \int_Ω} |u|-1)^2 $ over the space $W_0^{1,1}(\Omega )$. For $n$ large enough, the infimum is achieved in some sense on $BV(\Omega )$, and letting $n$ go to infinity this provides an approximation of the first eigenfunction for the first eigenvalue, since the term $n({\ds \int_Ω} |u|^2-1)^2$ "tends" to the constraint $\Vert u{\Vert }_1=1$.

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