• Sturm–Liouville Operators
• Spectral Theory
• Operator Theory
• Differential Equations
• Indefinite Inner Product Spaces
• Perturbation Theory

Refereed Publications

J. Behrndt, P. Schmitz, C. Trunk, Spectral bounds for indefinite singular Sturm–Liouville operators with uniformly locally integrable potentials. J. Differ. Equations 267 (2019),
468–493.
Preprint

J. Behrndt, P. Schmitz, C. Trunk, Spectral bounds for singular indefinite Sturm–Liouville operators with L1 -potentials. Proc. Am. Math. Soc. 146 (2018), 3935–3942.
Preprint

Conference Papers

J. Behrndt, P. Schmitz, C. Trunk, The non‐real spectrum of a singular indefinite Sturm–Liouville operator with regular left endpoint, Proc. appl. Math. Mech. 19 (2019).
Preprint

 J. Behrndt, B. Gsell, P. Schmitz, C. Trunk, An estimate on the non-real spectrum of a
singular indefinite Sturm–Liouville operator, Proc. appl. Math. Mech. 17 (2017), 859–860.
Preprint

J. Behrndt, P. Schmitz, C. Trunk, Bounds on the non-real spectrum of a singular indefinite Sturm–Liouville operator on R, Proc. appl. Math. Mech. 16 (2016), 881–882.
Preprint

Thesis

P. Schmitz, Zur WKB-Näherung für Lösungen gewöhnlicher Differentialgleichungen einer komplexen Veränderlichen.
Masterarbeit

P. Schmitz, Zur Selbstadjungiertheit regulärer Sturm-Liouville-Differentialoperatoren.
Bachelorarbeit