We study the minimum of the essential spectrum of canonical systems $J{u}^{\prime }=-zHu$. 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 (2020). Our key tool is oscillation theory.

中文翻译：

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规范系统的基本范围

我们研究规范系统的基本光谱的最小值 $Ĵ{ü}^{\prime }=-žHü$。我们的结果可以描述为具有纯离散光谱的系统表征的一般化和定量化版本，最近由Romanov和Woracek（2020）获得。我们的关键工具是振荡理论。