{ "id": "1505.07403", "version": "v1", "published": "2015-05-27T17:18:27.000Z", "updated": "2015-05-27T17:18:27.000Z", "title": "The first nontrivial eigenvalue for a system of $p-$Laplacians with Neumann and Dirichlet boundary conditions", "authors": [ "Leandro M. Del Pezzo", "Julio D. Rossi" ], "comment": "21 pages, 1 figure", "categories": [ "math.AP" ], "abstract": "We deal with the first eigenvalue for a system of two $p-$Laplacians with Dirichlet and Neumann boundary conditions. If $\\Delta_{p}w=\\mbox{div}(|\\nabla w|^{p-2}w)$ stands for the $p-$Laplacian and $\\frac{\\alpha}{p}+\\frac{\\beta}{q}=1,$ we consider $$ \\begin{cases} -\\Delta_pu= \\lambda \\alpha |u|^{\\alpha-2} u|v|^{\\beta} &\\text{ in }\\Omega,\\\\ -\\Delta_q v= \\lambda \\beta |u|^{\\alpha}|v|^{\\beta-2}v &\\text{ in }\\Omega,\\\\ \\end{cases} $$ with mixed boundary conditions $$ u=0, \\qquad |\\nabla v|^{q-2}\\dfrac{\\partial v}{\\partial \\nu }=0, \\qquad \\text{on }\\partial \\Omega. $$ We show that there is a first non trivial eigenvalue that can be characterized by the variational minimization problem $$ \\lambda_{p,q}^{\\alpha,\\beta} = \\min \\left\\{\\dfrac{\\displaystyle\\int_{\\Omega}\\dfrac{|\\nabla u|^p}{p}\\, dx +\\int_{\\Omega}\\dfrac{|\\nabla v|^q}{q}\\, dx} {\\displaystyle\\int_{\\Omega} |u|^\\alpha|v|^{\\beta}\\, dx} \\colon (u,v)\\in \\mathcal{A}_{p,q}^{\\alpha,\\beta}\\right\\}, $$ where $$ \\mathcal{A}_{p,q}^{\\alpha,\\beta}=\\left\\{(u,v)\\in W^{1,p}_0(\\Omega)\\times W^{1,q}(\\Omega)\\colon uv\\not\\equiv0\\text{ and }\\int_{\\Omega}|u|^{\\alpha}|v|^{\\beta-2}v \\, dx=0\\right\\}. $$ We also study the limit of $\\lambda_{p,q}^{\\alpha,\\beta} $ as $p,q\\to \\infty$ assuming that $\\frac{\\alpha}{p} \\to \\Gamma \\in (0,1)$, and $ \\frac{q}{p} \\to Q \\in (0,\\infty)$ as $p,q\\to \\infty.$ We find that this limit problem interpolates between the pure Dirichlet and Neumann cases for a single equation when we take $Q=1$ and the limits $\\Gamma \\to 1$ and $\\Gamma \\to 0$.", "revisions": [ { "version": "v1", "updated": "2015-05-27T17:18:27.000Z" } ], "analyses": { "keywords": [ "first nontrivial eigenvalue", "dirichlet boundary conditions", "first non trivial eigenvalue", "variational minimization problem", "limit problem interpolates" ], "note": { "typesetting": "TeX", "pages": 21, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv150507403D" } } }