ABSTRACT
Let Ω be a bounded domain in R m . We consider the eigenvalue problem Δ u + λ u = 0 in Ω u = 0 on ∂ Ω . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780203744369/d9858e60-9246-4876-bb34-38e3d28ecc5f/content/eq1811.tif"/>
