Matthieu Ostertag

I am an engineering student at Mines Nancy (Université de Lorraine), specialising in Industrial and Materials Engineering (GIM). I work on world models for industrial machines: latent dynamics models that predict how a process will evolve under candidate commands, and whether that knowledge survives the move to a machine the model has never seen.

From 2027 I will join École nationale des ponts et chaussées (ENPC, Institut Polytechnique de Paris) through its “Talents” track (formation complémentaire intégrée), in the Department of Applied Mathematics and Computer Science (IMI). I co-initiated Hack the World(s), a 24-hour hackathon on world models. Before that, I worked in strategy and engineering at Atos (London, Paris) and was a research intern at the German Aerospace Center (DLR), Institute of Materials Physics in Space (now part of the Institute for Frontier Materials), in Cologne, and at the French National Centre for Scientific Research (CNRS), ICMN laboratory, in Orléans.

Portrait of Matthieu Ostertag

Research

I am interested in world models that predict in representation space rather than in signal space, are conditioned on the actions a controller can take, and keep working when the sensing interface changes.

Source machine with 17 sensors (teal) and 4 commands (amber) → latent state → target machine. The same weights read both; the 7 sensors the target lacks (grey) simply drop out.

Ayoub Louaye Bouaziz, Matthieu Ostertag, Anton Demasles
arXiv preprint, 2026
project page arXiv code demo
bibtex
@misc{bouaziz2026worldmodelscrossmachinecnc,
  title         = {World Models for Cross-Machine CNC Transfer
                   under Partial Sensor Overlap},
  author        = {Ayoub Louaye Bouaziz and Matthieu Ostertag
                   and Anton Demasles},
  year          = {2026},
  eprint        = {2609.16071},
  archivePrefix = {arXiv},
  primaryClass  = {cs.LG},
  doi           = {10.48550/arXiv.2609.16071}
}

One set of weights reads any subset of a known sensor vocabulary. Locked on a CNC machine with 17 sensors and evaluated once, zero-shot, on a machine sharing only 10, the command-conditioned JEPA beats persistence but trails RevIN forecasters; a declared ablation shows that input normalization alone closes the gap, at a cost in calibration.

Next: verifying that the transferred model uses the commands, training on several source machines, and planning in the learned latent space.

Community

Hack the World(s) · co-initiator, steering committee
June 19–20, 2026 · Paris School of AI (PSL) and ESIEE Paris

A 24-hour hackathon on world models and JEPA architectures: 100 students from French engineering schools and universities, selected in 25 teams of four, supported through the night by 18 AI researchers and engineers as mentors. Sponsored by Yann LeCun, under the patronage of Philippe Baptiste, French Minister of Higher Education, Research and Space; organized with ESIEE Paris, Mines Nancy/ACADI and PR[AI]RIE, with support from AI Factory France.

Winning projects: a temporal JEPA predicting PDE dynamics in latent space (Gray-Scott), a JEPA world model trained on simulated Drosophila brain dynamics, and two-view self-supervision for rotation-invariant 3D shape features. The CNC project above started there.