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arXiv 2002.05465math.OCstat.COstat.ML
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非凸优化局部条件下随机梯度哈密顿蒙特卡洛的非渐近分析

Nonasymptotic analysis of Stochastic Gradient Hamiltonian Monte Carlo under local conditions for nonconvex optimization

Ömer Deniz Akyildiz, Sotirios Sabanis

AI总结:

本文在非对数凹的局部条件下分析SGHMC的Wasserstein-2非渐近收敛性,证明其步长一致控制精度,并给出非凸优化全局收敛、可扩展贝叶斯推断与泛化界。

摘要:

我们在不假设对数凹性的前提下,对随机梯度哈密顿蒙特卡洛(SGHMC)在Wasserstein-2距离下收敛至目标测度的过程进行了非渐近分析。我们的分析量化了SGHMC作为采样器在局部条件下的关键理论性质,显著改进了以往结果中的发现。具体而言,我们证明了目标分布与SGHMC的概率分布之间的Wasserstein-2距离可由算法步长一致控制,从而表明SGHMC能够在迭代次数方面一致地提供高精度结果。该分析还使我们能够获得局部条件下非凸优化问题的非渐近界,并意味着SGHMC被视为非凸优化器时,会以已知最优速率收敛至全局最小值。我们应用这些结果获得了可扩展贝叶斯推断的非渐近界以及非渐近泛化界。

英文摘要:

We provide a nonasymptotic analysis of the convergence of the stochastic gradient Hamiltonian Monte Carlo (SGHMC) to a target measure in Wasserstein-2 distance without assuming log-concavity. Our analysis quantifies key theoretical properties of the SGHMC as a sampler under local conditions which significantly improves the findings of previous results. In particular, we prove that the Wasserstein-2 distance between the target and the law of the SGHMC is uniformly controlled by the step-size of the algorithm, therefore demonstrate that the SGHMC can provide high-precision results uniformly in the number of iterations. The analysis also allows us to obtain nonasymptotic bounds for nonconvex optimization problems under local conditions and implies that the SGHMC, when viewed as a nonconvex optimizer, converges to a global minimum with the best known rates. We apply our results to obtain nonasymptotic bounds for scalable Bayesian inference and nonasymptotic generalization bounds.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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