The essential spectrum of canonical systems
arXiv:1908.02266
summary
The paper investigates the lower bound of the essential spectrum for canonical systems of the form Ju' = -zHu, extending previous characterizations of purely discrete spectra by applying oscillation theory.
Abstract
We study the minimum of the essential spectrum of canonical systems $Ju'=-zHu$. Our results can be described as a generalized and more quantitative version of the characterization of systems with purely discrete spectrum, which was recently obtained by Romanov and Woracek [6]. Our key tool is oscillation theory.
Topics & keywords
#canonical systems#essential spectrum#oscillation theory#discrete spectrum#spectral analysisessential spectrumcanonical systemsoscillation theoryspectral characterizationSturm-Liouvillemathematical physics