Coupling of the continuum and semiclassical limit. Part I: convergence of eigenvalues
Matthias Keller, Lorenzo Pettinari, Christiaan J. F. van de Ven
Abstract
We analyze the semiclassical $d$-dimensional Schrödinger operator in the continuum $ \frac{1}{2} Δ+ λ_N^2 V$ discretized on a mesh with spacing proportional to $1/N$. The semi-classical parameter $λ_N$ is chosen as $λ_N = N^{1 - γ}$, with $γ\in (-1,1)$, which ensures that $N$ governs both the semiclassical and continuum limit simultaneously. We prove that all eigenvalues of the discrete operator converge to those of the continuum, as $λ_N\to\infty$. Beyond this semi-classical domain, in the case of the harmonic oscillator, we further discuss the spectral asymptotics for $γ\in \mathbb{R} \setminus (-1,1)$, thereby fully characterizing the eigenvalue behavior across all possible values of $γ\in\mathbb{R}$.
