Status  Confirmed 
Seminar Series  SEMLPTMC 
Subjects  condmat.statmech 
Date  Monday 27 September 2021 
Time  10:45 
Institute  LPTMC 
Seminar Room  salle 523 du LPTMC  Tour 1213 Jussieu 
Speaker's Last Name  Hartmann 
Speaker's First Name  Alexander 
Speaker's Email Address  
Speaker's Institution  University of Oldenburg 
Title  Largedeviation simulations of rare nonequilibrium processes can be close to equilibrium 
Abstract  Fluctuation theorems like those of Crooks or Jarzynski allow to obtain equilibrium quantities from nonequilibrium processes. For example, the distribution P(W) of the work allows to extract the free energy difference $\Delta F$ between equilibrium starting state and final state, after hypothetical final equilibration. The region of P(W) where $W\approx\Delta F$ holds is most relevant to obtain $\Delta F$. But P(W) may be extremely small in this region, which makes in the case of computer simulations sophisticated largedeviation algorithms necessary. As example, the Ising model with work performed by changing the external field is shown, where probabilities as small as $10^{50}$ and lower must be reached. Going beyond the calculation of ΔF, we ask, how similar are the non equilibrium processes in this rareevent tail to the equilibrium ones that determine $\Delta F$? Here, this question is investigate for the unfolding and refolding of RNA secondary structures under influence of an external force f. Indeed the extreme lowprobability trajectories, which exhibit $W\approx\Delta F$ and thus contribute most to the determination of $\Delta F$ via Crooks equation, are very similar to the equilibrium trajectories. 
arXiv Preprint Number  
Comments  https://us06web.zoom.us/j/82938879975?pwd=Q3IvTmVtbFpXaVBFYVBvcDdtNzhOQT09 Meeting ID: 829 3887 9975 Passcode: 644686 
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