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Bibliographic Details
Main Authors: Zhou, Huanjian, Wang, Baoxiang, Sugiyama, Masashi
Format: Preprint
Published: 2024
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Online Access:https://arxiv.org/abs/2408.13045
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author Zhou, Huanjian
Wang, Baoxiang
Sugiyama, Masashi
author_facet Zhou, Huanjian
Wang, Baoxiang
Sugiyama, Masashi
contents In large-data applications, such as the inference process of diffusion models, it is desirable to design sampling algorithms with a high degree of parallelization. In this work, we study the adaptive complexity of sampling, which is the minimum number of sequential rounds required to achieve sampling given polynomially many queries executed in parallel at each round. For unconstrained sampling, we examine distributions that are log-smooth or log-Lipschitz and log strongly or non-strongly concave. We show that an almost linear iteration algorithm cannot return a sample with a specific exponentially small error under total variation distance. For box-constrained sampling, we show that an almost linear iteration algorithm cannot return a sample with sup-polynomially small error under total variation distance for log-concave distributions. Our proof relies upon novel analysis with the characterization of the output for the hardness potentials based on the chain-like structure with random partition and classical smoothing techniques.
format Preprint
id arxiv_https___arxiv_org_abs_2408_13045
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle The adaptive complexity of parallelized log-concave sampling
Zhou, Huanjian
Wang, Baoxiang
Sugiyama, Masashi
Data Structures and Algorithms
In large-data applications, such as the inference process of diffusion models, it is desirable to design sampling algorithms with a high degree of parallelization. In this work, we study the adaptive complexity of sampling, which is the minimum number of sequential rounds required to achieve sampling given polynomially many queries executed in parallel at each round. For unconstrained sampling, we examine distributions that are log-smooth or log-Lipschitz and log strongly or non-strongly concave. We show that an almost linear iteration algorithm cannot return a sample with a specific exponentially small error under total variation distance. For box-constrained sampling, we show that an almost linear iteration algorithm cannot return a sample with sup-polynomially small error under total variation distance for log-concave distributions. Our proof relies upon novel analysis with the characterization of the output for the hardness potentials based on the chain-like structure with random partition and classical smoothing techniques.
title The adaptive complexity of parallelized log-concave sampling
topic Data Structures and Algorithms
url https://arxiv.org/abs/2408.13045