Hamiltonians and Riccati Equations for Linear Systems with Unbounded Control and Observation Operators. - Christian Wyss; Birgit Jacob; Hans Zwart (SIAM J. Control. Optim., 2012)

Krylov type methods exploiting the quadratic numerical range. - Andreas Frommer; Birgit Jacob; Karsten Kahl; Christian Wyss; Ian Zwaan (CoRR, 2019)

Stability radius for infinite-dimensional interconnected systems. - Birgit Jacob; Sebastian Möller 003; Christian Wyss (Syst. Control. Lett., 2020)

Computing the quadratic numerical range. - Birgit Jacob; Lukas A. Vorberg; Christian Wyss (J. Comput. Appl. Math., 2025)