Coarse-graining Langevin dynamics using reduced-order techniques
This work provides a systematic reduced-order modeling approach for Langevin dynamics, addressing the reduction of stochastic noise, which is relevant for computational biophysics.
The authors formulate the reduction of the Langevin equation from bio-molecular models as a reduced-order modeling problem, using Galerkin projection to Krylov subspaces. They prove equivalence to moment-matching and show that for order less than six, the reduced model automatically satisfies the fluctuation-dissipation theorem.
This paper considers the reduction of the Langevin equation arising from bio-molecular models. To facilitate the construction and implementation of the reduced models, the problem is formulated as a reduced-order modeling problem. The reduced models can then be directly obtained from a Galerkin projection to appropriately defined Krylov subspaces. The equivalence to a moment-matching procedure, previously implemented in , 2), is proved. A particular emphasis is placed on the reduction of the stochastic noise, which is absent in many order-reduction problems. In particular, for order less than six we can show the reduced model obtained from the subspace projection automatically satisfies the fluctuation-dissipation theorem. Details for the implementations, including a bi-orthogonalization procedure and the minimization of the number of matrix multiplications, will be discussed as well.