OSGA: A fast subgradient algorithm with optimal complexity

This paper presents an algorithm for approximately minimizing a convex function in simple, not necessarily bounded convex, finite-dimensional domains, assuming only that function values and subgradients are available. No global information about the objective function is needed apart from a strong convexity parameter (which can be put to zero if only convexity is known). The worst case number of iterations needed to achieve a given accuracy is independent of the dimension and—apart from a constant factor—best possible under a variety of smoothness assumptions on the objective function.