20–23 mai 2025
Université Paris Cité
Fuseau horaire Europe/Paris

What does it take to make MCMC feasible in very high dimensions?

22 mai 2025, 11:50
20m
Buffon Amphitheater (Université Paris Cité)

Buffon Amphitheater

Université Paris Cité

15 rue Hélène Brion 75013 Paris
Talk ML Methodology Bayesian inferences

Orateur

Jakob Robnik (University of California at Berkeley)

Description

Sampling from high-dimensional distributions is an important tool in Bayesian inference problems, like cosmological field level inference and Bayesian neural networks (BNN).
Hamiltonian Monte Carlo and its tuning-free implementation NUTS have pushed the limits of typical dimensionalities where sampling is feasible. I will show that this limit can be pushed further by disposing of the Metropolis-Hastings adjustment, at the cost of introducing asymptotic bias. I will show how this bias can be controlled to be negligible compared to the Monte Carlo error, resulting in tuning-free implementations of unadjusted Hamiltonian, Langevin, and Microcanonical Langevin Monte Carlo. I will also show how it can be used to improve sampling performance with massive parallelization. Finally, I will show applications to real-world problems, including BNNs.

Author

Jakob Robnik (University of California at Berkeley)

Co-auteur

Prof. Uroš Seljak (University of California at Berkeley)

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