Computing transition paths for rare events
- Series
- Applied and Computational Mathematics Seminar
- Time
- Monday, August 23, 2010 - 13:00 for 1 hour (actually 50 minutes)
- Location
- Skiles 002
- Speaker
- Maria Cameron – U Maryland
I will propose two numerical approaches for minimizing the MFF. Approach<br />
I is good for high-dimensional systems and fixed endpoints. It is <br />
based on temperature relaxation strategy and Broyden's method. Approach<br />
II is good for low-dimensional systems and only one fixed endpoint. It<br />
is based on Sethian's Fast Marching Method.I will show the <br />
application of Approaches I and II to the problems of rearrangement of<br />
Lennard-Jones cluster of 38 atoms and of CO escape from the Myoglobin protein<br />
respectively.
At low temperatures, a system evolving according to the overdamped Langevin equation spends most of the time near the potential minima and performs rare transitions between them. A number of methods have been developed to study the most likely transition paths. I will focus on one of them: the MaxFlux Functional (MFF), introduced by Berkowitz in 1983.I will reintepret the MFF from the point of view of the Transition Path Theory (W. E & E. V.-E.) and show that the MaxFlux approximation is equivalent to the Eikonal Approximation of the Backward Kolmogorov Equation for the committor function.