Sampling normalizing constants in high dimensions using inhomogeneous diffusions
arXiv:1612.07583
Abstract
Motivated by the task of computing normalizing constants and importance sampling in high dimensions, we study the dimension dependence of fluctuations for additive functionals of time-inhomogeneous Langevin-type diffusions on . The main results are nonasymptotic variance and bias bounds, and a central limit theorem in the regime. We demonstrate that a temporal discretization inherits the fluctuation properties of the underlying diffusion, which are controlled at a computational cost growing at most polynomially with . The key steps include establishing Poincaré inequalities for time-marginal distributions of the diffusion and nonasymptotic bounds on deviation from Gaussianity in a martingale central limit theorem.