Spectral bounds for singular indefinite Sturm-Liouville operators with $L^1$--potentials

Jussi Behrndt, Philipp Schmitz, Carsten Trunk

The spectrum of the singular indefinite Sturm-Liouville operator $$A=\text{sgn}(\cdot )(-\frac{d^2}{d{x}^2}+q)$$ with a real potential $q\in L^1(\mathbb{R})$ covers the…