QLS guest Seminar - Friday 23 March

[Quantitative Life Sciences]

QUANTITATIVE LIFE SCIENCES  GUEST SEMINAR

Friday, 23 March 2018 at 11:00,
ICTP, Central Area, 2nd floor, old SISSA building


Speaker: Daniel M. Busiello - Dip. Fisica e Astronomia "Galileo Galilei" 
-  Universita' degli Studi di Padova


Title: Entropy Production in Non-equilibrium Systems

Abstract:
Systems out of equilibrium are characterized by a continuous exchange of 
energy and matter with the environment through different mechanisms, 
thus producing entropy at the macroscopic level. We study the entropy 
production of a discrete-state system with random transition rates and 
the injection of an external probability current. At stationarity, the 
entropy production is shown to be composed by two contributions whose 
exact distributions are evaluated in the large system size limit and 
close to equilibrium. The first one is related to a generalized Joule's 
law, while the second contribution has a Gaussian universal distribution 
which depends just on two topological parameters. In the second part of 
the talk we compare the entropy production of a Master Equation system 
with the one of the corresponding continuum limit, i.e. a Fokker-Planck 
equation. We demonstrate that the Seifert's formula for the entropy 
production provides just a lower bound for the exact entropy production. 
In fact, this formula ought to be corrected keeping into account 
information about the microscopic transition rates, and this correction 
survives in the continuum limit. This effect of the coarse-graining has 
shown to be glaring in the simple example of a n-step random walk. The 
difference between discrete-state systems and continuous systems in 
evaluating the entropy production has been addressed also in comparing 
non-equilibrium steady states, NESS, and stochastic pumping, SP. We show 
that the entropy production of a system with SP is greater than the one 
produced by a system in a NESS, generating the same (time-averaged) 
probability current and exhibiting the same (time-averaged) probability 
distribution.


Indico web page: http://indico.ictp.it/event/8557/

Everyone interested is most welcome to attend!

-- 
Erica Sarnataro
Group Secretary
Quantitative Life Sciences
The Abdus Salam International Centre for Theoretical Physics (ICTP)
Trieste,  Italy
Tel. +39-040-2240623
www.ictp.it/research/qls.aspx
e-mail: qls at ictp.it