2013/12/04 by Iutzeler, Franck, Bianchi, Pascal, Ciblat, Philippe +1 · 1 citation
#Distributed #FOS: Computer and information sciences #FOS: Mathematics #Optimization and Control (math.OC) #Parallel #and Cluster Computing (cs.DC)
paper · doi:10.48550/arxiv.1312.1085
Consider a set of N agents seeking to solve distributively the minimization problem infx ∑n = 1N fn(x) where the convex functions fn are local to the agents. The popular Alternating Direction Method of Multipliers has the potential to handle distributed optimization problems of this kind. We provide a general reformulation of the problem and obtain a class of distributed algorithms which encompass various network architectures. The rate of convergence of our method is considered. It is assumed that the infimum of the problem is reached at a point x_⋆, the functions fn are twice differentiable at this point and ∑ ∇2 fn(x_⋆) > 0 in the positive definite ordering of symmetric matrices. With these assumptions, it is shown that the convergence to the consensus x_⋆ is linear and the exact rate is provided. Application examples where this rate can be optimized with respect to the ADMM free parameter ρ are also given.