QLS Guest Seminar - Tuesday 7 June

[Quantitative Life Sciences]

QUANTITATIVE LIFE SCIENCES GUEST SEMINAR

Tuesday, 7 June at 2:00pm

ICTP, Central Area, 2nd floor, old SISSA building

Speaker: Sanjay Kumar - Department of Physics, Banaras Hindu University, 
Varanasi, India

Title: "Periodically Driven DNA: Theory and Simulations"

Abstract:
We propose a generic model of driven DNA under the influence of an 
oscillatory force of amplitude F and frequency /v/ and show the 
existence of a
dynamical transition for a chain of finite length. We find that the area 
of the hysteresis loop, A_loop , scales with the same exponents as 
observed in a
recent study based on a much more detailed model. However, towards the 
true thermodynamic limit, the high-frequency scaling regime extends to
lower frequencies for larger chain length L and the system has only one 
scaling A_loop ~ ν^-1 F^2 . Expansion of an analytical expression for 
A_loop
obtained for the model system in the low-force regime revealed that 
there is a new scaling exponent associated with force A_loop ~ ν^-1 
F^2.5 , which has been
validated by high-precision numerical calculation. By a combination of 
analytical and numerical arguments, we also deduce that for large but finite
L, the exponents are robust and independent of temperature and friction 
coefficient.

/References/:
1. Periodically driven DNA: Theory and Simulation
Sanjay Kumar, Ravinder Kumar and Wolfhard Janke Phys. Rev. E , 93, 
010402 (R)(2016)
2. Statistical mechanics of DNA unzipping under periodic force: Scaling 
behavior of hysteresis loop
Sanjay Kumar and Garima Mishra Phys. Rev. Lett. 110, 258102 (2013)

Indico web page: http://indico.ictp.it/event/7894/

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