On greedy multi-step inertial randomized Kaczmarz method for solving linear systems

Recently, the multi-step inertial randomized Kaczmarz (MIRK) method for solving large-scale linear systems was proposed in [17]. In this paper, we incorporate the greedy probability criterion into the MIRK method, along with the introduction of a tighter threshold parameter for this criterion. We prove that the proposed greedy MIRK (GMIRK) method enjoys an improved deterministic linear convergence compared to both the MIRK method and the greedy randomized Kaczmarz method. Furthermore, we exhibit that the multi-step inertial extrapolation approach can be seen geometrically as an orthogonal projection method, and establish its relationship with the sketch-and-project method [15] and the oblique projection technique [22]. Numerical experiments are provided to confirm our results.