Wassim Kabalan
Research Associate — AI for Physics, The Alan Turing Institute
I am a Research Associate at The Alan Turing Institute, where I work on AI for physics. During my PhD in computational cosmology I built differentiable simulation and inference software in JAX, from the statistical method down to the distributed GPU code, and several of these libraries are now used by other groups. Before the PhD I spent five years writing production C++ at Dassault Systèmes inside a multi-million-line codebase.
Education & Professional Experience
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Oct 2026 – present |
Research Associate, The Alan Turing Institute, London, UK AI for Physics team (Fundamental Research), with Jason McEwen. Physics-informed emulators and rigorous Bayesian uncertainty quantification. |
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Dec 2023 – Oct 2026 |
PhD in Computational Cosmology, Université Paris Cité — APC (CNRS/IN2P3), Paris, France Thesis: Differentiable Field-Level Cosmology: CMB, Weak Lensing, and GPU-Accelerated Inference. Advisors: Eric Aubourg, Alexandre Boucaud, Josquin Errard, François Lanusse.
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Apr 2023 – May 2023 |
Advanced AI for Data Analysis, École Polytechnique (Executive Education), Palaiseau |
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Oct 2019 – Oct 2023 |
3DEXPERIENCE & CATIA Software Infrastructure Engineer, Dassault Systèmes, Vélizy-Villacoublay, France
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Jan 2019 – Oct 2019 |
Data Acquisition Engineer, SERMA (for Renault), Guyancourt, France
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Sep 2016 – Sep 2018 |
M2, Electronics, Electrical & Automation, Université Gustave Eiffel |
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Sep 2013 – Nov 2016 |
Licence, Engineering Science, Université Paris-Est Créteil (UPEC) |
Collaborations
- LSST Dark Energy Science Collaboration (DESC) — Member; weak-lensing forward models and scalable, differentiable simulation tools (
JaxPM,jax-fli). - Simons Observatory — Member; component separation tooling (
FURAX) for CMB analysis.
Open-Source Software
jax-fli— Author. JAX-based field-level inference package; fully distributed, high-resolution N-body and lensing simulations.jaxDecomp— Author / Maintainer. JAX library for distributed 3D domain decomposition and FFTs: NVIDIA cuDecomp bindings (multi-GPU, NCCL) plus a pure-JAX backend for portability across CUDA / TPU / CPU.JaxPM— Main contributor / Maintainer. Differentiable particle-mesh simulations in JAX with multi-accelerator support; used for weak-lensing forward modeling.jax-healpy— Main contributor / Maintainer. JAX-native HEALPix utilities; AD-friendly, GPU-ready.FURAX— Main contributor / Maintainer. JAX framework for inverse problems; used for Simons Observatory CMB component separation.
Talks & Tutorials
- Generative AI with JAX [Tutorial] • AISSAI School 2025 • Oct 2025 slides
- JAXPM: Scalable and Differentiable Particle-Mesh Simulations • Bayesian Deep Learning Workshop • May 2025 slides
- Bayesian Inference for Cosmology with JAX [Tutorial] • Bayesian Deep Learning Workshop • May 2025 slides
- Massively Parallel Computing in Cosmology with JAX [Tutorial] • CoPhy 2024 • Nov 2024 slides
- Differentiable and Distributed Particle-Mesh N-body Simulations • LSST France 2024 • Jun 2024 slides
Publications
Refereed
Kabalan, W., Lanusse, F., Boucaud, A., and Aubourg, E. 2026. jaxDecomp: JAX Library for 3D Domain Decomposition and Parallel FFTs. Journal of Open Source Software, 11(121), 8852. https://doi.org/10.21105/joss.08852.
Spagnoletti, A., Boucaud, A., Huertas-Company, M., Kabalan, W., and Biswas, B. 2024. Bayesian Deconvolution of Astronomical Images with Diffusion Models: Quantifying Prior-Driven Features in Reconstructions. arXiv:2411.19158 [astro-ph.IM]. Contribution: JAX-based deconvolution code, multi-node simulations on Jean Zay HPC.
Sommer, K., Kabalan, W., and Brunet, R. 2024. Infrared Radiometric Image Classification and Segmentation of Cloud Structure Using Deep-learning Framework for Ground-based Infrared Thermal Camera Observations. EGUsphere Preprint 2024-101. Contribution: JAX-based U-Net implementation and training on Jean Zay HPC. Code: github.com/ASKabalan/infrared-cloud-detection
Preprints
- Kabalan, W., Rizzieri, A., Sohn, W., Basyrov, A., Boucaud, A., Beringue, B., Chanial, P., Tsang King Sang, E., and Errard, J. 2026. A GPU-Accelerated JAX Framework for Robust Parametric Component Separation and Clustering Optimization for CMB Polarization Satellites. arXiv:2604.08463 [astro-ph.CO].
In Preparation
- Kabalan, W., Lanusse, F., Boucaud, A., and Aubourg, E. 2026. Differentiable Forward Modelling for Field-Level Inference in Stage IV Weak Lensing Surveys.
Supervision
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Jan 2025 – Jun 2025 |
Binh Nguyen, Master 1 Student Project: Inference of Weak-Lensing Parameters from Blended Galaxies Using Generative Neural Networks. Final report. Outcome: Talk at Rencontres du Vietnam. |
Skills
Programming Python (7y), JAX (3y), C++ (5y), CUDA (3y), PyTorch (1y)
HPC & GPU Computing NCCL, MPI, Slurm, Nsight; multi-node GPU (up to 512 H100s), distributed FFTs, custom CUDA primitives via XLA FFI/CustomCall
Statistics & Machine Learning High-dimensional Bayesian inference (MCMC, HMC, NUTS) with NumPyro / BlackJAX; simulation-based and field-level inference; generative deep learning; uncertainty quantification
DevOps & Software Engineering GitHub/GitLab CI, packaging (PyPI), containers, Linux, CMake, TDD
Languages
| French | Native |
| English | Professional proficiency (C1) |
| Arabic | Native |
| German | Basic (A2) |

