Scalable Generative Sampling and Multilevel Estimation for Lattice Field Theories Near Criticality

Fuente: arXiv
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Main Authors: Singha, A., Kauffmann, J., Cellini, E., Jansen, K., Nakajima, S.
Format: Preprint
Published: 2026
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author Singha, A.
Kauffmann, J.
Cellini, E.
Jansen, K.
Nakajima, S.
author_facet Singha, A.
Kauffmann, J.
Cellini, E.
Jansen, K.
Nakajima, S.
contents Sampling lattice field theories near criticality is severely hindered by critical slowing down, which makes standard Markov chain methods increasingly inefficient at large lattice volumes. We introduce a multiscale generative sampler, inspired by renormalization-group ideas, that models the Boltzmann distribution through a coarse-to-fine hierarchy across length scales. At each level, a conditional Gaussian mixture model captures the main local dependence of newly introduced variables on the already-sampled coarse field, while a masked continuous normalizing flow refines the remaining conditional structure. Coarse levels encode the dominant long-wavelength modes, and finer levels progressively add short-distance fluctuations. In addition, because the architecture preserves coarse fields exactly during refinement, it provides exact restriction maps at no additional computational cost and directly enables unbiased Multilevel Monte Carlo (MLMC) variance reduction. For the two-dimensional scalar $ϕ^4$ theory at criticality, the method achieves integrated autocorrelation times orders of magnitude smaller than Hybrid Monte Carlo (HMC) on large volumes, maintains high importance-sampling efficiency relative to other generative baselines, and reproduces unbiased physical observables in statistical agreement with long HMC simulations.
format Preprint
id arxiv_https___arxiv_org_abs_2604_10209
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Scalable Generative Sampling and Multilevel Estimation for Lattice Field Theories Near Criticality
Singha, A.
Kauffmann, J.
Cellini, E.
Jansen, K.
Nakajima, S.
High Energy Physics - Lattice
Statistical Mechanics
Computational Physics
Sampling lattice field theories near criticality is severely hindered by critical slowing down, which makes standard Markov chain methods increasingly inefficient at large lattice volumes. We introduce a multiscale generative sampler, inspired by renormalization-group ideas, that models the Boltzmann distribution through a coarse-to-fine hierarchy across length scales. At each level, a conditional Gaussian mixture model captures the main local dependence of newly introduced variables on the already-sampled coarse field, while a masked continuous normalizing flow refines the remaining conditional structure. Coarse levels encode the dominant long-wavelength modes, and finer levels progressively add short-distance fluctuations. In addition, because the architecture preserves coarse fields exactly during refinement, it provides exact restriction maps at no additional computational cost and directly enables unbiased Multilevel Monte Carlo (MLMC) variance reduction. For the two-dimensional scalar $ϕ^4$ theory at criticality, the method achieves integrated autocorrelation times orders of magnitude smaller than Hybrid Monte Carlo (HMC) on large volumes, maintains high importance-sampling efficiency relative to other generative baselines, and reproduces unbiased physical observables in statistical agreement with long HMC simulations.
title Scalable Generative Sampling and Multilevel Estimation for Lattice Field Theories Near Criticality
topic High Energy Physics - Lattice
Statistical Mechanics
Computational Physics
url https://arxiv.org/abs/2604.10209