Long-Time Convergence of an Adaptive Biasing Force Method: Variance Reduction by Helmholtz Projection

Orateur: AlRACHID Houssam
Localisation: ENPC, France
Type: Séminaire des doctorants
Site: UPEM
Salle: 4B08R
Date de début: 11/02/2015 - 10:00
Date de fin: 11/02/2015 - 10:00

Free energy computation techniques are very important in molecular dynamics computations, in order to obtain a coarse-grained description of a high-dimensional complex physical system. We propose an improvement of the adaptive biasing force (ABF) method, by projecting the estimated mean force onto a gradient. The associated stochastic process satisfies a non linear stochastic differential equation. Using entropy techniques, we prove exponential convergence to the stationary state of this stochastic process. We finally show on some numerical examples that the variance of the approximated mean force is reduced using this technique, which makes the algorithm more efficient than the standard ABF method.