## On the stability of sequential Monte Carlo methods in high dimensions.(English)Zbl 1304.82070

Sequential Monte Carlo (SMC) methods form a collection of techniques that approximate a sequence of distributions, known up to the normalizing constant and of increasing dimension. They combine importance sampling and resampling to approximate a target distribution. The paper addresses the stability of a SMC for targets in $$\mathbb R^d$$ for large $$d$$. It is known that using a single importance sampling step, one produces an approximation to the target which deteriorates as $$d$$ increases, unless the number of Monte Carlo samples $$N$$ increases at an exponential rate in $$d$$. The problem is bypassed by introducing a sequence of artificial targets beginning from any density and approaching the target of interest. The SMC method is used to sample from the obtained sequence. It is found that in high dimensions, SMC algorithms can efficiently control the variability of the importance sampling weights and estimate fixed-dimensional marginals at a cost which is less than exponential in $$d$$. The resampling leads here to a reduction of the Monte Carlo error and an increase in the effective sample size (ESS). All of the analysis is carried out under an assumption that the target density is i.i.d.

### MSC:

 82C80 Numerical methods of time-dependent statistical mechanics (MSC2010) 60K35 Interacting random processes; statistical mechanics type models; percolation theory 60F99 Limit theorems in probability theory 62F15 Bayesian inference 65C05 Monte Carlo methods 91G60 Numerical methods (including Monte Carlo methods)
Full Text: