Asymptotics of eigenvalues of the Schroedinger operator with a strong delta-interaction on a loop

Abstract

In this paper we investigate the operator $H_{\beta}=-\Delta-\beta\delta(\cdot-\Gamma)$ in $L^{2}({\Bbb R}^{2})$, where $\beta>0$ and $\Gamma$ is a closed $C^{4}$ Jordan curve in ${\Bbb R}^{2}$. We obtain the asymptotic form of each eigenvalue of $H_{\beta}$ as $\beta$ tends to infinity. We also get the asymptotic form of the number of negative eigenvalues of $H_{\beta}$ in the strong coupling asymptotic regime.