Estimates of the principal eigenvalue of the -Laplacian and the -biharmonic operator
We survey recent results concerning estimates of the principal eigenvalue of the Dirichlet -Laplacian and the Navier -biharmonic operator on a ball of radius in and its asymptotics for approaching and . Let tend to . There is a critical radius of the ball such that the principal eigenvalue goes to for and to for . The critical radius is for any for the -Laplacian and in the case of the -biharmonic operator. When approaches , the principal eigenvalue of the Dirichlet...