Transition Pathways of Rare Reactive Events in Complex Systems
February 4, 2009 3pm, 204 SEC
Abstract
The dynamics of biomolecular systems is typically characterized by a
wide range of time scales, complicating their study via computer
simulations. Of particular difficulty are situations which involve
rare reactive events such as conformation changes of macromolecules,
nucleation events during first-order phase transitions, chemical
reactions, or bistable behavior of genetic switc. The occurrence of
these rare events is related to the presence of dynamical bottlenecks
of energetic and/or entropic origin which effectively partition the
configuration space of the system into metastable basins. The system
spends most of its time fluctuating within these long-lived metastable
states and only rarely makes transitions between them. The rare
events then determine the long-time evolution of the system.
In this talk, I will present a general theoretical framework termed
transition path theory (TPT) for the description of
rare reactive events and compare it to other approaches such as the
classical transition state theory (TST) and the more recent
transition path sampling (TPS). I will also show that TPT can used to
design efficient numerical
algorithms such as the string method for the identification of the
pathway, free energy and rate of the rare events.
Both the theory and the numerics will be illustrated via examples.
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Last modified: April 11 2016 - 18:14:43