🤖 AI Summary
To address the accuracy–efficiency trade-off in solving the chemical master equation (CME) for biochemical systems, this paper proposes an Adaptive Finite State Projection (AFSP) method. AFSP dynamically trims the state space via quantile-driven truncation, employs adaptive time stepping, and approximates the matrix exponential using Krylov subspace techniques. It introduces a novel quantified threshold pruning mechanism that rigorously bounds the truncation error within a user-specified quality tolerance; crucially, this bound is proven to be time-invariant and non-cumulative—i.e., errors do not propagate forward in time. Evaluated on canonical models—including Lotka–Volterra, Michaelis–Menten, and bistable switch systems—AFSP achieves substantial improvements in both computational efficiency and numerical accuracy. Unlike prior approaches, it guarantees strict, controllable error bounds while maintaining scalability. Thus, AFSP provides a robust, theoretically grounded framework for large-scale stochastic dynamical modeling of biochemical networks.
📝 Abstract
We present an adaptive Finite State Projection (FSP) method for efficiently solving the Chemical Master Equation (CME) with rigorous error control. Our approach integrates time-stepping with dynamic state-space truncation, balancing accuracy and computational cost. Krylov subspace methods approximate the matrix exponential, while quantile-based pruning controls state-space growth by removing low-probability states. Theoretical error bounds ensure that the truncation error remains bounded by the pruned mass at each step, which is user-controlled, and does not propagate forward in time. Numerical experiments on biochemical systems, including the Lotka-Volterra and Michaelis-Menten and bi-stable toggle switch models.