BooksecrCollected Volumepp. 419–432

# Spectral asymptotics induced by approaching and diverging planar circles

• ### Sylwia Kondej

University of Zielona Góra, Poland
We consider two dimensional system governed by the Hamiltonian with delta interaction supported by two concentric circles separated by distance $d$. We analyze the asymptotics of the discrete eigenvalues for $d \to 0$ as well as for $d\to \infty$.