Fisher information lower bounds for sampling

Autor: Chewi, Sinho, Gerber, Patrik, Lee, Holden, Lu, Chen
Rok vydání: 2022
Předmět:
Druh dokumentu: Working Paper
Popis: We prove two lower bounds for the complexity of non-log-concave sampling within the framework of Balasubramanian et al. (2022), who introduced the use of Fisher information (FI) bounds as a notion of approximate first-order stationarity in sampling. Our first lower bound shows that averaged LMC is optimal for the regime of large FI by reducing the problem of finding stationary points in non-convex optimization to sampling. Our second lower bound shows that in the regime of small FI, obtaining a FI of at most $\varepsilon^2$ from the target distribution requires $\text{poly}(1/\varepsilon)$ queries, which is surprising as it rules out the existence of high-accuracy algorithms (e.g., algorithms using Metropolis-Hastings filters) in this context.
Comment: 35 pages
Databáze: arXiv