论文标题

通过闭环阻尼通过惯性动力学进行快速优化

Fast optimization via inertial dynamics with closed-loop damping

论文作者

Attouch, Hedy, Bot, Radu Ioan, Csetnek, Ernö Robert

论文摘要

为了开发快速优化方法,在希尔伯特空间$ h $中,我们分析了渐近行为,因为时间$ t $倾向于无穷大,惯性连续动力学,在这种动力上,阻尼是闭环控制。函数$ f:h \ to r $要最小化(不一定是凸)通过IT梯度进入动态,这被认为是lipchitz在$ h $的有限子集上连续的。这提供了具有非线性阻尼和非线性驱动力的自主动力系统。我们首先考虑阻尼项$ \ partial ϕ(\ dot {x}(t))$的情况,充当速度的闭环控制。阻尼电位$ ϕ:h \ to [0,+\ infty)$是凸的连续函数,可在原点下实现其最小值。我们展示了对关联的库奇问题的全球解决方案的存在和独特性。然后,我们分析生成的生成轨迹的渐近收敛性。我们使用优化,控制理论和PDE的技术:基于能量函数的降低属性,准差异和库尔迪卡 - 洛贾斯维奇理论,单调算子理论的波浪样方程理论。收敛率是根据数据$ F $和$ ϕ $的几何特性获得的。当$ f $强烈凸出时,我们提供提供指数收敛率的一般条件。然后,我们将结果扩展到额外的Hessian驱动阻尼进入动态的情况,从而减少振荡。最后,我们考虑一个惯性系统,涉及速度$ \ dot {x}(t)$和梯度$ \ nabla f(x(t))$。除了其最初的结果外,这项工作还调查了近年来致力于连续的惯性动力学和数值算法之间相互作用的众多作品,以进行优化,重点是自主系统,闭环自适应程序和收敛速度。

In a Hilbert space $H$, in order to develop fast optimization methods, we analyze the asymptotic behavior, as time $t$ tends to infinity, of inertial continuous dynamics where the damping acts as a closed-loop control. The function $f: H \to R$ to be minimized (not necessarily convex) enters the dynamic through it gradient, which is assumed to be Lipschitz continuous on the bounded subsets of $H$. This gives autonomous dynamical systems with nonlinear damping and nonlinear driving force. We first consider the case where the damping term $\partial ϕ(\dot{x}(t))$ acts as a closed-loop control of the velocity. The damping potential $ϕ: H \to [0,+\infty)$ is a convex continuous function which achieves its minimum at the origin. We show the existence and uniqueness of a global solution to the associated Cauchy problem. Then, we analyze the asymptotic convergence properties of the generated trajectories generated. We use techniques from optimization, control theory, and PDE's: Lyapunov analysis based on the decreasing property of an energy-like function, quasi-gradient and Kurdyka-Lojasiewicz theory, monotone operator theory for wave-like equations. Convergence rates are obtained based on the geometric properties of the data $f$ and $ϕ$. When $f$ is strongly convex, we give general conditions which provide exponential convergence rates. Then, we extend the results to the case where an additional Hessian-driven damping enters the dynamic, which reduces the oscillations. Finally, we consider an inertial system involving jointly the velocity $\dot{x}(t)$ and the gradient $\nabla f(x(t))$. In addition to its original results, this work surveys the numerous works devoted in recent years to the interaction between continuous damped inertial dynamics and numerical algorithms for optimization, with the emphasis on autonomous systems, closed-loop adaptive procedures, and convergence rates.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源