Quasi-Newton Compatible Actor-Critic for Deterministic Policies

The recent paper titled 'Quasi-Newton Compatible Actor-Critic for Deterministic Policies' presents a novel second-order deterministic actor-critic framework that builds upon the classical deterministic policy gradient method. By integrating curvature information from the performance function, the authors introduce a quadratic critic that not only preserves the true policy gradient but also approximates the performance Hessian. This innovation allows for a least-squares temporal difference learning scheme to efficiently estimate the quadratic critic parameters. Consequently, the framework enables a quasi-Newton actor update, resulting in faster convergence compared to traditional first-order methods. The numerical examples provided in the paper demonstrate significant improvements in convergence and performance over standard deterministic actor-critic baselines. This general applicability to any differentiable policy class positions the proposed method as a substantial advancement in th…