TY - JOUR ID - Pielichowski2008 LB - Pielichowski2008 AU - Pielichowski, Wacław TI - Some remarks on the optimization of eigenvalue problems involving the p-Laplacian ST - Some remarks on the optimization of eigenvalue problems involving the p-Laplacian JO - Opuscula Math. JA - Opuscula Math. JF - Opuscula Mathematica PY - 2008 VL - 28 IS - 4 SP - 561 EP - 566 DO - http://dx.doi.org/10.7494/OpMath.2008.28.4.561 UR - http://dx.doi.org/10.7494/OpMath.2008.28.4.561 AB - Given a bounded domain \(\Omega \subset \mathbb{R}^n\), numbers \(p \gt 1\), \(\alpha \geq 0\) and \(A \in [0,|\Omega |]\), consider the optimization problem: find a subset \(D \subset \Omega \), of measure \(A\), for which the first eigenvalue of the operator \(u\mapsto -\text{div} (|\nabla u|^{p-2}\nabla u)+ \alpha \chi_D |u|^{p-2}u \) with the Dirichlet boundary condition is as small as possible. We show that the optimal configuration \(D\) is connected with the corresponding positive eigenfunction \(u\) in such a way that there exists a number \(t\geq 1\) for which \(D=\{u \leq t\}\). We also give a new proof of symmetry of optimal solutions in the case when \(\Omega \) is Steiner symmetric and \(p = 2\). KW - \(p\)-Laplacian KW - the first eigenvalue KW - Steiner symmetry SN - 1232-9274 ER -