Ensemble-based gradient inference for particle methods in optimization and sampling

Author(s): Claudia Schillings, Claudia Totzeck, Philipp Wacker
Venue: arXiv
Year: 2022

Paper: https://arxiv.org/abs/2209.15420

Abstract

We propose an approach based on function evaluations and Bayesian inference to extract higher-order differential information of objective functions from a given ensemble of particles. Pointwise evaluation \(\{V(x^i)\}_i\) of some potential \(V\) in an ensemble \(\{x^i\}_i\) contains implicit information about first or higher order derivatives, which can be made explicit with little computational effort (ensemble-based gradient inference – EGI). We suggest to use this information for the improvement of established ensemble-based numerical methods for optimization and sampling such as Consensus-based optimization and Langevin-based samplers. Numerical studies indicate that the augmented algorithms are often superior to their gradient-free variants, in particular the augmented methods help the ensembles to escape their initial domain, to explore multimodal, non-Gaussian settings and to speed up the collapse at the end of optimization dynamics.

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