Singularly perturbed periodic and semiperiodic differential operators

V. A. Mikhailets, V. M. Molyboga

Qualitative and spectral properties of the form-sums S_{\pm}(V):=D_{\pm}^{2m}\dotplus V(x),\quad m\in \mathbb{N}, in the Hilbert space $L_2(0,1)$ are studied. Here the periodic $…