In 1911 year, when Weyl is a young mathematician specticlizing in integrable system and PDE, He proved the important result about the asystomztion of eigenvalues of Dirichelet problem in $latex \Omega\subset R^n$ is a compact domain;i.e. $latex N(\lambda)=(2\pi)^d Vol(\Omega)\lambda^{\frac{d}{2}}(1+o(1))$ Which in fact is a conjecture of *** in *** in published in 1910. This is definitely a very amazing achievement of mathematician, The realist meaning we can actually charge with the spectrum as…
