Regret bounds for Gaussian process bandits without observation noise

• Main Author: Zoghi, Masrour
• Language: English
• Published: University of British Columbia 2012
• Online Access: http://hdl.handle.net/2429/42865

This thesis presents some statistical refinements of the bandits approach presented in [11] in the situation where there is no observation noise. We give an improved bound on the cumulative regret of the samples chosen by an algorithm that is related (though not identical) to the UCB algorithm of [11] in a complementary setting. Given a function f on a domain D ⊆ R^d , sampled from a Gaussian process with an anisotropic kernel that is four times differentiable at 0, and a lattice L ⊆ D, we show that if the points in L are chosen for sampling using our branch-and-bound algorithm, the regret asymptotically decreases according to O(e^{τt/(ln t)^{d/4}}) with high probability, where t is the number of observations carried out so far and τ is a constant that depends on the objective function. === Science, Faculty of === Computer Science, Department of === Graduate