2024/02/13 by F. Della Pietra, Della Pietra, F.
Computer Science · Mathematics · #Advanced Mathematical Modeling in Engineering #Spectral Theory in Mathematical Physics #Nonlinear Partial Differential Equations
paper · pdf · doi:10.48550/arxiv.2402.08474
The aim of this paper is to obtain optimal estimates for the first Robin eigenvalue of the anisotropic p-Laplace operator, namely: λF(β,Ω)=λF(p,β,Ω)= min_ψ∈ W1,p(Ω)∖\0\ \frac∫ΩF(∇ ψ)p dx +β∫∂Ω|ψ|p F(νΩ) d\mathcal HN-1 ∫Ω|ψ|p dx where p∈]1,+∞[, Ω is a bounded, convex domain in \mathbb RN, νΩ is its Euclidean outward normal, β is a real number, and F is a sufficiently smooth norm on \mathbb RN. We show an upper bound for λF(β,Ω) in terms of the first eigenvalue of a one-dimensional nonlinear problem, which depends on β and on the volume and the anisotropic perimeter of Ω, in the spirit of the classical estimates of Pólya \citepo61 for the Euclidean Dirichlet Laplacian. We will also provide a lower bound for the torsional rigidity τp(β,Ω)p-1 = max_\substackψ∈ W1,p(Ω)∖\0\ \dfrac(∫Ω|ψ| dx)p∫ΩF(∇ψ)p dx+β∫∂Ω|ψ|p F(νΩ) d\mathcal HN-1 , when β>0. The obtained results are new also in the case of the classical Euclidean Laplacian.