
About. My name is Nesta van der Schaaf (he/him). I'm a postdoctoral researcher at Inria Saclay, working in the QuaCS group of the Laboratoire Méthodes Formelles. I'm broadly interested in mathematical physics, category theory, locale theory, and more. Currently, my research focuses on point-free and categorical foundations of order and causality theory.
Two of the main aims are to provide a point-free mathematical foundation for spacetimes and relativity theory, and to study concurrency in categorical quantum mechanics.
Recently, I have also been working on duality theory and quantum foundations.
See here for news.
Preprint, arXiv:2605.04038.
[arXiv]Proceedings of AiML 2026, EPTCS 447, pp. 584–602; with Marco Lewis.
To appear in Journal of Mathematical Physics; with Chris Heunen.
Journal of Pure and Applied Algebra, vol. 288(7), pp. 107654; with Chris Heunen.
Bulletin of the London Mathematical Society, vol. 56(4), pp. 1532-1549; with Chris Heunen and Andre Kornell.
Cahiers de Topologie et Géométrie Différentielle Catégoriques LXII.2 (2021), pp. 177-238.
Accepted talk at TACL 2026, 28 July 2026.
Accepted talk at LRB26, 15 July 2026; with Chris Heunen. [slides]
Accepted talk at LRB26, 14 July 2026; with Marco Lewis. [slides]
Accepted talk at Logic Colloquium 2026, 30 June 2026. [slides]
Informal expository lecture at QuaCS category theory seminar, 17 March, 2026.
Invited talk at QLOC seminar, 3 March 2026; with Chris Heunen.
Joint with Marco Lewis, QuaCS seminar, 6 June 2025.
QuaCS seminar, 23 January 2025.
Accepted talk at PSSL 109, 17 November 2024; with Chris Heunen. [slides]
Accepted talk at Causalworlds, 19 September 2024; with Chris Heunen and Prakash Panangaden. [recording]
Accepted talk at IQSA 2024, 26 July 2024; with Chris Heunen and Prakash Panangaden.
Invited talk at Oxford Quantum Lunch, 21 March 2024; with Chris Heunen and Prakash Panangaden. [slides]
Invited talk at the Birmingham Theory Seminar, 1 March 2024. [slides][abstract]
Edinburgh Category Theory Seminar, 8 November 2023; with Chris Heunen. [slides][abstract]
Students in Theoretical and Mathematical Physics Seminar, 5 October 2023; with Chris Heunen and Prakash Panangaden. [abstract]
Plenary talk at QPL 2023, 19 July 2023; with Chris Heunen and Andre Kornell. [slides]
Parallel talk at QPL 2023, 18 July 2023; with Chris Heunen. [ppt]
Students in Theoretical and Mathematical Physics Seminar, 23 March 2023; with Chris Heunen and Andre Kornell. [slides]
Edinburgh Category Theory Seminar, 18 January 2023; with Chris Heunen and Andre Kornell. [slides]
Quantum Software Lab Workshop, 13 December 2022; with Chris Heunen and Andre Kornell. [event][slides][recording]
Short lecture series on causality in point-free topology at Sejny Summer Institute, July 2022. [slides]
Department presentation of my MSc thesis, 26 June 2020. [slides]
Two-part lecture series on Lie groupoids at the Radboud Noncommutative Geometry Seminar, 8 December, 2018.
Two-part lecture series on Lie groupoids at the Radboud Noncommutative Geometry Seminar, 4 December, 2018.
Lecture for final project of course on C*-algebras, January 2018. [notes]
Lecture for master seminar course, 23 October 2017. [notes]
Department presentation of my BSc thesis, 12 June 2017. [slides]
PhD thesis, University of Edinburgh, supervised by Chris Heunen, 10 May 2024.
MSc thesis, Radboud University, supervised by Klaas Landsman, June 2020. Main result published as [1].
BSc thesis, Radboud University, supervised by Klaas Landsman, August 2017.
Joint research project on concurrency in monoidal categories for the Adjoint School, part of ACT 2023.
Literature study. Proves the characterisation of Morita equivalence of C*-algebras in terms of invertible bimodules, 2018-2020. [notes]
Final project for a course on C*-algebras. Gives an overview of the characterisation of projective unitary representations of locally compact Hausdorff groups in terms of twisted group C*-algebras, January 2018. [notes]