Annali di Matematica Pura ed Applicata ( IF 1.0 ) Pub Date : 2021-03-04 , DOI: 10.1007/s10231-021-01073-x Giane C. Rampasso , Noemi Wolanski
In the present article we study a minimization problem in \(\mathbb R^N\) involving the perimeter of the positivity set of the solution u and the integral of \(|\nabla u|^{p(x)}\). Here p(x) is a Lipschitz continuous function such that \(1<p_\mathrm{min}\le p(x)\le p_\mathrm{max}<\infty \). We prove that such a minimizing function exists and that it is a classical solution to a free boundary problem. In particular, the reduced free boundary is a \(C^2\) surface and the dimension of the singular set is at most \(N-8\). Under further regularity assumptions on the exponent p(x) we get more regularity of the free boundary. In particular, if \(p\in C^\infty \) we have that \(\partial _\mathrm{red}\{u>0\}\) is a \(C^\infty \) surface.
中文翻译:
p(x)-Laplacian涉及区域的最小化问题。
在本文中,我们研究\(\ mathbb R ^ N \)中的最小化问题,该问题涉及解u的正集合的周长和\(| \ nabla u | ^ {p(x)} \)的积分。这里p(x)是一个Lipschitz连续函数,使得\(1 <p_ \ mathrm {min} \ le p(x)\ le p_ \ mathrm {max} <\ infty \)。我们证明存在这样的最小化函数,并且它是自由边界问题的经典解决方案。特别地,减小的自由边界是\(C ^ 2 \)曲面,奇异集的维数最多为\(N-8 \)。在指数p(x),我们可以得到更多的自由边界规则性。特别是,如果\(p \ in C ^ \ infty \)我们有\(\ partial _ \ mathrm {red} \ {u> 0 \} \)是\(C ^ \ infty \)曲面。