It’s a pleasure to announce the next PH seminar talk on Wednesday, April 1, 4 pm (CEST), with Michal Wojtylak (Jagiellonian University) on:

Title: Linear algebra of dissipative Hamiltonian systems.

Abstract:
We will begin with a review of the Kronecker of pencils appearing in the port Hamiltonian modelling.  Although the task  seems to be completed by  [1], and [2], the transfer function considerations in  [3] put a different light on these results.

In the second part of the talk we will concentrate on the eigenvalue infinity, and the size of the largest Kronecker block -  the index.
We will study  the perturbation properties of the eigenvalue infinity, presenting non-asymptotic results based on the Bauer-Fike theorem, see [4].   Several numerical examples will be considered.

[1] C. Mehl, V. Mehrmann, and M. Wojtylak. Matrix pencils with coefficients that have positive
semidefinite Hermitian parts. SIMAX 2022.

[2]  N. Gillis, V. Mehrmann, and P. Sharma. Computing the nearest stable matrix pairs. NLAA, 2018.

[3] K. Cherifi, H. Gernandt, and D. Hinsen. The difference between port-Hamiltonian, passive and
positive real descriptor systems. MCSS,  2024.

[4] H. Blazhko, M. Wojtylak, Detection of the higher order Kronecker blocks by perturbation, 2026 , preprint.


You can participate via the following Zoom-Link

Meeting-ID: 687 5689 8101
Password:mV0dd94q
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