Joost J. Joosten and Domènec Ruiz-Balet joined the Centre de Recerca Matemàtica as affiliated researchers in January 2026. Joosten joins the group in Combinatorics and Mathematics of Computer Science, and Ruiz-Balet joins the group in Partial Differential Equations.

Joost J. Joosten studied Physics and Mathematics at the University of Amsterdam before turning fully to mathematical logic, the field in which he later completed his PhD at Utrecht University on interpretability logics. Postdoctoral stays in Prague, Utrecht, Amsterdam and Seville followed, along with a period in risk management, before a Ramón y Cajal fellowship brought him to Barcelona, where he joined the Department of Logic, History and Philosophy of Science at the Universitat de Barcelona. He has been a member of the IMUB since 2011 and was elected to the Academia Europaea in 2024. Since 2022, he holds an ICREA Acadèmia stipend. His research spans proof theory, ordinal analysis, philosophical logic, and logic applied to computer science and law.

Domènec Ruiz-Balet is an Assistant Professor at the Universitat de Barcelona. His research focuses on the mathematics of machine learning, particularly on areas at the intersection of partial differential equations and dynamical systems, such as deep neural networks and transformers. He also works on mathematical economics, in particular mean-field games and broader game theory. Last January, he co-organised the workshop Mathematical Foundations of Machine Learning: PDEs, Probability, and Dynamics at the CRM, which brought together researchers connecting machine learning with tools from partial differential equations, dynamical systems and probability.

With their arrival, the CRM’s community of affiliated researchers reaches close to one hundred. The CRM extends a warm welcome to both.