🤖 AI Summary
This work addresses the challenge of efficiently exploring high-probability states in multimodal distributions within high-dimensional binary spaces, where conventional parallel tempering MCMC methods suffer from poor performance due to their reliance on rejection-free sampling. To overcome this limitation, we propose an Adaptive Importance Tempering algorithm that enhances Informed Importance Tempering (IIT) by incorporating an adaptive bounded balancing function, thereby substantially improving sampling efficiency while preserving the target distribution. We present two equivalent implementations—A-IIT and SS-IIT—both integrating adaptive mechanisms, rejection-free MCMC updates, and a parallel tempering framework. Experimental results demonstrate that the proposed approach outperforms IIT, RF-MH, and their multiple-try variants in identifying high-probability states under high-dimensional multimodal settings.
📝 Abstract
Based on the algorithm Informed Importance Tempering (IIT) proposed by Li et al. (2023) we propose an algorithm that uses an adaptive bounded balancing function. We argue why implementing parallel tempering where each replica uses a rejection free MCMC algorithm can be inefficient in high dimensional spaces and show how the proposed adaptive algorithm can overcome these computational inefficiencies. We present two equivalent versions of the adaptive algorithm (A-IIT and SS-IIT) and establish that both have the same limiting distribution, making either suitable for use within a parallel tempering framework. To evaluate performance, we benchmark the adaptive algorithm against several MCMC methods: IIT, Rejection free Metropolis-Hastings (RF-MH) and RF-MH using a multiplicity list. Simulation results demonstrate that Adaptive IIT identifies high-probability states more efficiently than these competing algorithms in high-dimensional binary spaces with multiple modes.