Probabilistic Linear Multistep Methods
This work provides a probabilistic extension to classical ODE solvers, offering error quantification with minimal computational overhead, which is incremental but useful for applications requiring uncertainty estimates in numerical solutions.
The authors tackled the problem of solving ordinary differential equations by deriving probabilistic versions of Adams-Bashforth and Adams-Moulton linear multistep methods from a Gaussian process framework, showing that the posterior mean and standard deviation can exactly match deterministic values and local truncation error, with empirical convergence rates demonstrated up to fifth order.
We present a derivation and theoretical investigation of the Adams-Bashforth and Adams-Moulton family of linear multistep methods for solving ordinary differential equations, starting from a Gaussian process (GP) framework. In the limit, this formulation coincides with the classical deterministic methods, which have been used as higher-order initial value problem solvers for over a century. Furthermore, the natural probabilistic framework provided by the GP formulation allows us to derive probabilistic versions of these methods, in the spirit of a number of other probabilistic ODE solvers presented in the recent literature. In contrast to higher-order Runge-Kutta methods, which require multiple intermediate function evaluations per step, Adams family methods make use of previous function evaluations, so that increased accuracy arising from a higher-order multistep approach comes at very little additional computational cost. We show that through a careful choice of covariance function for the GP, the posterior mean and standard deviation over the numerical solution can be made to exactly coincide with the value given by the deterministic method and its local truncation error respectively. We provide a rigorous proof of the convergence of these new methods, as well as an empirical investigation (up to fifth order) demonstrating their convergence rates in practice.