Dr. Kellian Cottart

Current research

Kellian Cottart I hold a PhD in machine learning and neuromorphic computing from Université Paris-Saclay, prepared under the supervision of Damien Querlioz at the Centre de Nanosciences et de Nanotechnologies (C2N). I defended my thesis on 5 October 2026.

My thesis is about Bayesian metaplasticity. Each weight of a network keeps a measure of its own uncertainty, and that uncertainty decides how much the weight may still move: what to remember, and what to forget. With Djohan Bonnet we turned this into an update rule that learns and forgets without being told where one task ends (Nature Communications, 2025). I then carried it over to binary weights, where a Bayesian network otherwise saturates and stops learning, so that it can run on hardware that stores a single bit per synapse (ICML 2026). The thesis also exists as a four-and-a-half-minute animation, with its transcript.

The work is part of the Metaspin project, which builds energy-efficient computing systems inspired by the brain, funded by the European Innovation Council (EIC). Along the way I have helped the device physicists at C2N turn magneto-ionic devices into synapses.

Latest paper all publications

Latest writing all posts

Talks & appearances all talks

  1. Oct 2026
    PhD defence, Palaiseau

    Bayesian metaplasticity. The video is a 4½-minute animated summary of the thesis. video

  2. Jul 2026
    ICML 2026, Seoul

    Poster. Active continual learning with metaplastic binary Bayesian neural networks slidesposter

  3. Sep 2025
    Neuromorphic Symposium, Paris

    Talk, 15 min. Bayesian continual learning and forgetting in neural networks slides