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Establish an acceleration phenomenon for sampling analogous to Nesterov’s acceleration in optimization

Determine whether there exists a sampling algorithm for strongly log-concave target distributions that achieves an accelerated convergence rate analogous to Nesterov’s accelerated gradient descent (e.g., a dependence on the condition number comparable to O(√κ)), and rigorously prove such an accelerated mixing phenomenon or provide a matching impossibility result.

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Background

The text draws a parallel between optimization and sampling, highlighting that Nesterov’s accelerated method achieves improved dependence on the condition number κ in optimization. The underdamped Langevin diffusion provides faster practical sampling but no established acceleration matching Nesterov’s phenomenon.

The authors emphasize that an acceleration phenomenon fully analogous to Nesterov’s is not yet established for sampling, identifying this as an intriguing open question.

References

This remarkable result, which saves a factor of $\sqrt\kappa$ over the basic rate for gradient descent, has been dubbed the acceleration phenomenon, and it remains an intriguing open question to establish such a phenomenon for sampling.

Statistical optimal transport (2407.18163 - Chewi et al., 25 Jul 2024) in Section: Sampling, Subsection: Some recent developments (Algorithms)