On the estimations of the small periodic eigenvalues
Summary: We estimate the small periodic and semiperiodic eigenvalues of Hill's operator with sufficiently differentiable potential by two different methods. Then using it we give the high precision approximations for the length of \(n\)th gap in the spectrum of Hill-Schrödinger operator and for the length of \(n\)th instability interval of Hill's equation for small values of \(n\). Finally we illustrate and compare the results obtained by two different ways for some examples.
scientific article; zbMATH DE number 6306060