The task of recovering a low-rank matrix from its noisy linear measurements plays a central role in computational science. Smooth formulations of the problem often exhibit an undesirable phenomenon: the condition number, classically defined, scales poorly with the dimension of the ambient space. In contrast, we here show that in a variety of concrete circumstances, nonsmooth penalty formulations do not suffer from the same type of ill-conditioning. Consequently, standard algorithms for nonsmooth optimization, such as subgradient and prox-linear methods, converge at a rapid dimension-independent rate when initialized within constant relative error of the solution. Moreover, nonsmooth formulations are naturally robust against outliers. Our framework subsumes such important computational tasks as phase retrieval, blind deconvolution, quadratic sensing, matrix completion, and robust PCA. Numerical experiments on these problems illustrate the benefits of the proposed approach.

该研究提出了一种新的低秩矩阵恢复方法，采用非平滑惩罚形式，在某些具体情况下能够克服传统平滑方法的病态问题，同时具有自适应性和鲁棒性。数值实验说明了该方法在解决相位恢复、盲卷积、矩阵补全和稳健PCA等计算任务中的优势。

具有复合优化的低秩矩阵恢复：良好的条件和快速收敛