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arXiv 2407.04562math.OC
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从随机微分方程视角看具有时变粘性和几何阻尼的随机惯性梯度动力学

An SDE Perspective on Stochastic Inertial Gradient Dynamics with Time-Dependent Viscosity and Geometric Damping

Rodrigo Maulen-Soto, Jalal Fadili, Hedy Attouch, Peter Ochs

AI总结:

本文利用随机Lyapunov分析研究带时变粘性阻尼和Hessian驱动阻尼的二阶随机惯性微分方程,证明了凸优化中函数值的几乎必然收敛与期望快速收敛,并给出了凸和强凸情形下的复杂性收敛速率。

摘要:

我们的方法是连续耗散动力系统与优化算法之间紧密联系的一部分。我们旨在通过由目标函数梯度驱动的随机惯性微分方程来求解凸极小化问题。这将为分析具有随机梯度输入的快速优化算法提供一个一般的数学框架。我们的研究是对我们先前致力于时间一阶随机最速下降工作的自然延伸。我们的目标是通过考虑时间二阶随机微分方程,纳入粘性时变阻尼和Hessian驱动阻尼,进一步发展这些结果。为了实施这一计划,我们依赖于随机Lyapunov分析。假设扩散项乘以一个依赖于粘性阻尼的函数满足平方可积条件,并且Hessian驱动阻尼是一个正常数,我们的第一个主要结果表明,几乎必然地,函数值收敛,并且函数值在期望意义下快速收敛。此外,在Hessian驱动阻尼为零的情况下,我们得到了函数值在期望意义下和几乎必然意义下的快速收敛,我们还证明了轨迹的几乎必然弱收敛。通过为凸和强凸情形建立若干新的逐点和遍历期望收敛速率,我们提供了全面的复杂性分析。

英文摘要:

Our approach is part of the close link between continuous dissipative dynamical systems and optimization algorithms. We aim to solve convex minimization problems by means of stochastic inertial differential equations which are driven by the gradient of the objective function. This will provide a general mathematical framework for analyzing fast optimization algorithms with stochastic gradient input. Our study is a natural extension of our previous work devoted to the first-order in time stochastic steepest descent. Our goal is to develop these results further by considering second-order stochastic differential equations in time, incorporating a viscous time-dependent damping and a Hessian-driven damping. To develop this program, we rely on stochastic Lyapunov analysis. Assuming a square-integrability condition on the diffusion term times a function dependant on the viscous damping, and that the Hessian-driven damping is a positive constant, our first main result shows that almost surely, there is convergence of the values, and states fast convergence of the values in expectation. Besides, in the case where the Hessian-driven damping is zero, we conclude with the fast convergence of the values in expectation and in almost sure sense, we also managed to prove almost sure weak convergence of the trajectory. We provide a comprehensive complexity analysis by establishing several new pointwise and ergodic convergence rates in expectation for the convex and strongly convex case.

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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