Research.

I am largely interested in mathematical questions of a dynamical nature, e.g., in the context of algorithm design, control systems and synthetic biology. In particular, I like to understand the interplay between the underlying problem structure and achievable qualitative behaviour. We typically study these questions by means of appropriate topological invariants.

Projects.

(Under construction, available this winter.)

Selected (pre)prints.

[p2] Asymptotic stability equals exponential stability—while you twist your eyes

sample-image Wouter Jongeneel
Submitted 2024.
PDF, arXiv, bibtex, invex to convex GIF, South Pole attractor GIF
Charles Conley himself posed the following ``converse question'' in the late 1970s: ``To what extent does the homotopy index itself determine the equivalence class of isolated invariant sets which are related by continuation?'' [p. 83, Con78]. This question, as revitalized by Matthew Kvalheim [Kva23], inspired our work .... Specifically, the abstract of our work reads as: ``Suppose that two vector fields on a smooth manifold render some equilibrium point globally asymptotically stable (GAS). We show that there exists a homotopy between the corresponding semiflows such that this point remains GAS along this homotopy.''

Comment added May 30, 2025: Updated version, contains a section on ISS.

Books.

[B1] Topological Obstructions to Stability and Stabilization: History, Recent Advances and Open Problems

sample-image Wouter Jongeneel and Emmanuel Moulay
SpringerBriefs in Control, Automation and Robotics (Open Access), pp. X, 132, 2023.
PDF available here, Springer website, supported by the SNSF
About this book (text by Springer): This open access book provides a unified overview of topological obstructions to the stability and stabilization of dynamical systems defined on manifolds and an overview that is self-contained and accessible to the control-oriented graduate student ... . The authors review the interplay between the topology of an attractor, its domain of attraction, and the underlying manifold that is supposed to contain these sets. They present some proofs of known results in order to highlight assumptions and to develop extensions, and they provide new results showcasing the most effective methods to cope with these obstructions to stability and stabilization. Moreover, the book shows how Borsuk’s retraction theory and the index-theoretic methodology of Krasnosel’skii and Zabreiko underlie a large fraction of currently known results. This point of view reveals important open problems, and for that reason, this book is of interest to any researcher in control, dynamical systems, topology, or related fields.

Journal papers.

[J4] Small errors in random zeroth-order optimization are imaginary

sample-image Wouter Jongeneel, Man-Chung Yue and Daniel Kuhn
SIAM Journal on Optimization (SIOPT), vol. 34, no. 3, pp. 2638 - 2670, 2024.
PDF, arXiv, link (SIAM), bibtex, Lorenz GIF
*Winner of the 2023 INFORMS Optimization Society Student Paper Prize (slides).

[J3] On continuation and convex Lyapunov functions

sample-image Wouter Jongeneel and Roland Schwan
IEEE Transactions on Automatic Control (TAC), vol. 69, no. 10, pp. 6895 - 6906, 2024.
PDF, arXiv, link (IEEE), bibtex, Bifurcation GIF

[J2] Efficient Learning of a Linear Dynamical System with Stability Guarantees

sample-image Wouter Jongeneel, Tobias Sutter and Daniel Kuhn
IEEE Transactions on Automatic Control (TAC), vol. 68, no. 5, pp. 2790 - 2804, 2023.
arXiv, link (IEEE), bibtex
As presented at the SIAM Conference on Optimization 2023 (slides). *Runner up IEEE CSS Swiss Chapter Young Author Best Journal Paper Award 2023, part of the TAC special issue on Learning and Control.

[J1] Topological Linear System Identification via Moderate Deviations Theory

sample-image Wouter Jongeneel, Tobias Sutter and Daniel Kuhn
IEEE Control Systems Letters, vol. 6, pp. 307-312, 2022.
arXiv, link (IEEE), bibtex
Presented at the 2021 CDC.

Peer-reviewed conference proceedings.

[C5] Ordering and refining path-complete Lyapunov functions through composition lifts

sample-image Wouter Jongeneel and Raphaël M. Jungers
IEEE Conference on Decision and Control (CDC), 2025 (accepted, to appear).
arXiv
In this note, we close Conjecture 8.20, as posed in the wonderful thesis by Debauche.

[C4] A Large Deviations Perspective on Policy Gradient Algorithms

sample-image Wouter Jongeneel, Daniel Kuhn and Mengmeng Li (alphabetic)
Proceedings of the 6th Annual Learning for Dynamics & Control Conference (L4DC), PMLR vol. 242, pp. 916 - 928, 2024.
arXiv, link (PLMR), bibtex

[C3] On topological properties of compact attractors on Hausdorff spaces

sample-image Wouter Jongeneel
European Control Conference (ECC), pp. 186 - 191, 2024.
PDF, arXiv, link (IEEE), bibtex

[C2] On Topological Equivalence in Linear Quadratic Optimal Control

sample-image Wouter Jongeneel and Daniel Kuhn
European Control Conference (ECC), pp. 2002 - 2007, 2021.
PDF, link (IEEE), bibtex

[C1] Robust Linear Quadratic Regulator: Exact Tractable Reformulation

sample-image Wouter Jongeneel, Tyler Summers and Peyman Mohajerin Esfahani
IEEE Conference on Decision and Control (CDC), pp. 6742 - 6747, 2019.
PDF, link (IEEE), bibtex

Preprints (under review, under construction, ...).

[p3] A generalized global Hartman-Grobman theorem for asymptotically stable semiflows

sample-image Wouter Jongeneel
2025.
PDF, arXiv
The abstract reads as: ``Recently, Kvalheim and Sontag provided a generalized global Hartman-Grobman theorem for equilibria under asymptotically stable continuous vector fields. By leveraging topological properties of Lyapunov functions, their theorem works without assuming hyperbolicity [KS25]. We extend their theorem to a class of possibly discontinuous vector fields, in particular, to vector fields generating asymptotically stable semiflows.''

Comment added June 3, 2025: Minor update, see arXiv.

[p1] Imaginary Zeroth-Order Optimization

sample-image Wouter Jongeneel
Submitted 2022.
PDF, arXiv, bibtex
As presented at the International Conference on Continuous Optimization 2022.

Extended abstracts.

Comment added March 20, 2025: An extended version is in preparation for both [E1] and [E2].

[E2] On Preorders of Path-complete Lyapunov Functions Through Lifts

sample-image Wouter Jongeneel and Raphaël M. Jungers
Benelux Meeting on Systems and Control, p. 50, 2025.
link (book of abstracts)

[E1] On the Conley Index and Controllability

sample-image Wouter Jongeneel
Benelux Meeting on Systems and Control, p. 219, 2025.
link (book of abstracts)

Thesis.

[PhD] Stability: a search for structure

sample-image Wouter Jongeneel
PhD Thesis, Electrical Engineering, EPFL Jun. 2024, adviser Prof. Daniel Kuhn.
link (EPFL)

[MSc] Controlling the Unknown: A Game Theoretic Perspective

sample-image Wouter Jongeneel
MSc Thesis, Systems & Control, TU Delft Nov. 2019, adviser Prof. Peyman Mohajerin Esfahani.
link (TU Delft)

Other notes.

[n1] Stability via reverse I-projections, a symplectic perspective on the computation

Wouter Jongeneel
Technical note, 2022.
PDF

With special thanks to Raphaël Jungers, Daniel Kuhn, Mengmeng Li, Peyman Mohajerin Esfahani, Emmanuel Moulay, Roland Schwan, Tyler Summers, Tobias Sutter and Man-Chung Yue. Throughout, kindly supported by the EU, EPFL, TU Delft, NCCR Automation, SNSF and UCLouvain.