Complex Systems Group

Physics Department of Bu-Ali Sina University

In our research group we are working on the following subjects:

  • Markov processes
  • Large deviations theory
  • Non-equilibrium statistical mechanics
  • Stochastic modeling of Gene expression
  • Exacxtly solvable models

Recent Projects

  • Current fluctuations in a stochastic system of classical particles with next-nearest-neighbor interactions

    Sara Kaviani and Farhad H. Jafarpour

    A 1D totally asymmetric exclusion process consisting of classical particles with next-nearest-neighbor interactions has been considered on a discrete lattice with a ring geometry. Using large deviation techniques, we have investigated fluctuations of particle current in the system. In the two-particle sector, we have obtained the large deviation function of the particle current. In this sector, we have also found the effective potential that the particles experience when an atypical particle current is generated. Numerical results in the three-particle sector have also been presented.

  • Stochastic modeling of gene expression: application of ensembles of trajectories

    Pegah Torkaman and Farhad H. Jafarpour

    It is well established that gene expression can be modeled as a Markovian stochastic process and hence proper observables might be subjected to large fluctuations and rare events. Since dynamics is often more than statics, one can work with ensembles of trajectories for long but fixed times, instead of states or configurations, to study dynamics of these Markovian stochastic processes and glean more information. In this paper we aim to show that the concept of ensemble of trajectories can be applied to a variety of stochastic models of gene expression and hence, apart from asymptotic behavior of remote tails of probability distributions of the dynamical observables, generating functions for the cumulants of these observables can easily be obtained. We start with the simplest stochastic model of gene expression and then extend our approach to more sophisticated and yet more realistic models.

Members

Current and graduated
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Farhad H. Jafarpour

Group Leader

Resume

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Pegah Torkaman (Behrad)

Graduated

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Sara Kaviani

Graduated

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S. A. A. Terohid

Graduated

Resume

Contact us

Bu-Ali Sina University

College of basic sceinces, Physics department, Shahid Mostafa Ahmadi Roshan Street, Hamedan, Iran
Postcode: 6516738695
Tel: 081-38381601