Felix L. Schwenninger

collaborators

10 papers

math.CA2026

A solution to Crouzeix's conjecture

Emiel Lorist, Felix Schwenninger

We provide a proof of Crouzeix's conjecture, which combines the tools developed previously for weaker estimates with a simple perturbation lemma for $2$ -dilations. Applying the lem…

math.OC2026

Coercive quadratic converse ISS Lyapunov theorems for linear analytic systems

Andrii Mironchenko, Felix Schwenninger

We derive converse Lyapunov theorems for input-to-state stability (ISS) of linear infinite-dimensional analytic systems. While we show that ISS in general does not imply the existe…

math.FA2026

The lattice structure of negative Sobolev and extrapolation spaces

Sahiba Arora, Jochen GlÃ¼ck, Felix L. Schwenninger

It is well-known that the Sobolev spaces $W^{k, p} (R^{d})$ are vector lattices with respect to the pointwise almost everywhere order if $k \in {0, 1}$ , but not if $k \geq 2$ .…

math.FA2026

Laplace-Carleson embeddings and infinity-norm admissibility

Birgit Jacob, Jonathan R. Partington, Sandra Pott +2

A full characterization of the boundedness of Laplace--Carleson embeddings on $L^{\infty}$ is provided, in terms of the Carleson intensity of the respective measure and of a suitable…

math.AP2026

A universal example for quantitative semi-uniform stability

Sahiba Arora, Felix Schwenninger, Ingrid Vukusic +1

We characterise quantitative semi-uniform stability for $C_{0}$ -semigroups arising from port-Hamiltonian systems, complementing recent works on exponential and strong stability. With…

math.FA2025

Admissible operators for sun-dual semigroups

Sahiba Arora, Felix L. Schwenninger

We extend classical duality results by Weiss on admissible operators to settings where the dual semigroup lacks strong continuity. This is possible using the sun-dual framework, wh…