On the Realization of Finite Essential Spectra
of Oscillation Exponents of Two-Dimensional
Differential Systems
摘要
Abstract
For any finite set of nonnegative numbers containing zero, we construct a two-dimensionallinear homogeneous differential system (periodic if all elements of the given set are pairwisecommensurate) in which the spectra of the oscillation exponents of signs, zeros, roots, andhyperroots coincide with this set, and all the values of these exponents are essential.