Convergence analysis of the indefinite proximal augmented lagrange method under strongly convex conditions
摘要
The augmented Lagrangian method (ALM) is a fundamental framework for solving convex optimization problems with linear constraints, and its convergence has been extensively studied. Its proximal variant, known as the Proximal ALM, improves stability by adding a positive-definite quadratic proximal term, which regularizes the primal subproblem at each iteration. Recently, an indefinite proximal augmented Lagrangian method (IDP-ALM) was proposed, which relaxes the requirement for a positive-definite quadratic proximal term. This approach allows for a broader range of parameter choices while still guaranteeing convergence. In this paper, we focus on relaxing the parameter range of the IDP-ALM. Specifically, we extend its parameter range under the strong convexity assumption of the objective function and establish its convergence under this condition. With respect to the convergence rate, we demonstrate that IDP-ALM achieves an ergodic convergence rate of