Apparaît dans la collection : Schlumberger workshop - Computational and statistical trade-offs in learning

We consider online convex optimization with noisy zero-th order information, that is noisy function evaluations at any desired point. We focus on problems with high degrees of smoothness, such as online logistic regression. We show that as opposed to gradient-based algorithms, high-order smoothness may be used to improve estimation rates, with a precise dependence on the degree of smoothness and the dimension. In particular, we show that for infinitely differentiable functions, we recover the same dependence on sample size as gradient-based algorithms, with an extra dimension-dependent factor. This is done for convex and strongly-convex functions in constrained or global optimization (with either one point or two points noisy evaluations of the functions). Joint work with F. Bach.