My CV
Publications
Talks
Teaching
Numerics
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Contact

clement.royer@lamsade.dauphine.fr
Clément Royer
Université Paris Dauphine-PSL
Place du Maréchal de Lattre de Tassigny
75016 Paris
FRANCE
I am also on Google Scholar and Github.

Clément W. Royer

Associate professor, Université Paris Dauphine-PSL


Pour la version française de cette page, cliquez ici.

Latest news

  • Talk (2026/04) I gave a talk in the Image working group of the MAP5, in Paris, France. My slides on nonconvex phase retrieval and unbalanced optimal transport can be accessed here.
    Thanks to the Mathematics for Image team for hosting me!

  • Talk (2026/04) I gave a talk in the MMSID team seminar of the Laboratoire d'Informatique Gaspard Monge, in Marne-la-Vallée, France. My slides on trust-region methods and phase retrieval can be accessed here.
    Thanks to Théo Lacombe and to the team for having me!

  • Accepted paper (2026/03) The paper Direct-search methods for decentralized blackbox optimization, co-authored with El Houcine Bergou, Youssef Diouane and Vyacheslav Kungurstev, has appeared in Optimization Methods and Software.

  • Talk (2026/03) I gave a talk in the Algorithms and Combinatorial Optimization team of the Laboratoire d'Informatique de Paris Nord, in Villetaneuse, France. My slides on positive spanning sets and their links with polyhedra can be accessed here.
    Thanks to Luca Ferrarini for the invitation, and for the entire team for hosting me!

  • Talk (2026/03) I gave a talk in the Statistics and Optimization seminar of the Mathematical Institute of Toulouse (Toulouse, France). My talk on derivative-free optimization for black-box attacks can be found here.
    Thanks to the MISFIT team for organizing this visit!

  • Talk (2026/02) I gave a seminar in the Applied Mathematics Unit, part of the French Engineering school ENSTA (Palaiseau, France). My talk on strict saddle functions can be found here.
    Thank you to the group for having me!

  • Teaching (2026/01) I have started my Optimization for Machine Learning class in Dauphine's IASD (AI, Systems, Data) part-time master program.

  • Accepted paper (2025/12) The paper A line search framework with restarting for noisy optimization problems, co-authored with Albert S. Berahas and Michael J. O'Neill, has appeared in Computational Optimization and Applications.

  • Talk (2025/12) I gave a talk in the Statistics seminar of the Laboratoire de Probabilités, Statistique et Modélisation in Paris, France. My slides on restarted line-search methods for nonconvex optimization can be found here.
    Thanks a lot to Tam Le for the warm welcome!

  • Defence (2025/11) Sébastien Kerleau defended his PhD thesis at Université Paris Dauphine-PSL on November 24. Sébastien's thesis was co-supervised by Denis Cornaz and myself, and studied positive spanning sets (PSSs) and their connections with graph theory. Thanks to the thesis committee (Charles Audet, Mourad Baiou, Roland Grappe, Aurélie Lagoutte) and congratulations Sébastien !

  • New preprint (2025/11) Complexity guarantees and polling strategies for Riemannian direct-search methods, co-authored with Bastien Cavarretta, Florentin Goyens and Florian Yger.
    A great effort led by Bastien on generating good directions for derivative-free optimization on Riemannian manifolds!

  • Teaching (2025/11) I am teaching two short courses in Dauphine's MODO (Decision and Optimization) Master program: Stochastic Programming and Machine Learning for Optimization.

  • Defence (2025/09) Iskander Legheraba defended his PhD thesis at Université Paris Dauphine-PSL on September 26. His doctoral work, co-supervised by Yann Chevaleyre and myself, revolves around landscape and complexity analyses in nonconvex optimization. Thanks to the committee (Youssef Diouane, Serge Gratton, Elisa Riccietti, Irène Waldspurger), and congratulations Iskander!

  • Defence (2025/09) I defended my habilitation à diriger des recherches on September 22 at Université Paris Dauphine-PSL. My coordinator was Antonin Chambolle, my reviewers were Coralia Cartis, Alexandre d'Aspremont, Edouard Pauwels, and the head of the committee was Anne Auger. Thanks to the five of them for their feedback, and to everyone who attended this defence!
    My habilitation thesis is available here while my defence slides can be found here.

  • Teaching (2025/09) I am acting as deputy director (CS track) for the IASD (Artificial Intelligence, Systems, Data) Master program from Dauphine and PSL. I have also started my lectures on Optimization for Machine Learning in that program, as well as my classes on Mathematics for Data Science (first year of Master in Computer Science, Dauphine) and Optimization for Data Science (second year of Master in Computer Science and Management, Dauphine). Off to a busy Fall!

  • Conference (2025/08) I attended the Optimization unplugged workshop held at EPFL (Lausanne, Switzerland) on August 25-27. A great event with terrific talks (including blackboard ones!). Many thanks to the organizers Nicolas Boumal, Lénaïc Chizat, Nicolas Flammarion and Andrew McRae!

    Research interests

    My research essentially revolves around the field of numerical optimization and its applications, particularly in complex systems and data science. In addition to optimization, my work relies heavily on linear algebra techniques and randomized methods.
    Lately I have been interested in analyzing certain classes of nonconvex optimization problems and developing efficient algorithms with complexity guarantees for solving those problems. I am also highly interested in derivative-free optimization and its applications to solving simulation-based problems.

    Short bio

  • September 22, 2025: Habilitation to Supervise Research, defended at Université Paris Dauphine-PSL.

  • September 1st, 2019: Joined Université Paris Dauphine-PSL and LAMSADE as a maître de conférences (equivalent to associate professor, with tenure granted on September 1st, 2020).

  • November 2016-August 2019: Postdoctoral research associate within the Wisconsin Institute for Discovery, in Madison, Wisconsin (USA). I was fortunate to work in the group of Stephen J. Wright.

  • November 4, 2016: PhD in applied mathematics from the university of Toulouse, delivered by the Université Toulouse III Paul Sabatier. Prepared at the Institut de Recherche en Informatique de Toulouse, under the joint supervision of Serge Gratton and Luís Nunes Vicente.

  • For more information, you can have a look at my vitae in a short or extended format.

    Materials on this page are available under Creative Commons CC BY-NC 4.0 license.