Minimization of the first eigenvalue in problems involving the bi-laplacian

Abstract

This paper concerns the minimization of the first eigenvalue in problems involvingthe bi-Laplacian under either homogeneous Navier boundary conditions or homogeneousDirichlet boundary conditions. Physically, in case of N = 2, our equation modelsthe vibration of a non homogeneous plate which is either hinged or clamped alongthe boundary. Given several materials (with different densities) of total extension ||,we investigate the location of these materials inside so to minimize the first modein the vibration of the corresponding plate.Keywords: bi-Laplacian, first eigenvalue, minimization.Este art´?culo trata de la minimizaci´on del primer autovalor en problemas relativosal bi-Laplaciano bajo condiciones de frontera homog´eneas de tipo Navier o Dirichlet.F´?sicamente, en el problema bi-dimensional, nuestra ecuacin modela la vibraci´on deuna placa inhomog´enea fija con goznes a lo largo de su borde. Dados varios materiales(de diferentes densidades) y extensi´on total ||, investigamos cu´al debe serla localizaci´on de tales materiales en la placa para minimizar el primer modo de suvibraci´on.Palabras clave: bi-Laplaciano, primer autovalor, minimizaci´on.