Description |
Tridib Sadhu(TIFR Mumbai) Abstract: Although basic equilibrium concepts like state variables, thermodynamic potentials, etc do not straightforwardly extend for non-equilibrium states, an analogue of Landau free energy characterising macroscopic fluctuations could be defined based on a mathematical theory of large deviations. I shall present a few old and new exact results for such a quantity in a class of non-equilibrium transport models. These are interacting classical many-body systems with relations to quantum spin chains. Our new results show that similar to a thermodynamic potential, these free-energy-analogues are robust against variations of coupling with external baths, thereby strengthening the possibility of a thermodynamic description for non-equilibrium states. I shall explain how these exact results are derived using a tilted operator formalism and a matrix-product-representation for a specific integrable model [1]. Then, I shall recover these results using a minimal action solution of a hydrodynamic field theory [2], which applies to a wider class of systems, including those which are non-integrable. Refs. [1] Derrida, Hirschberg, Sadhu, 182 (2021) J Stat Phys; [2] in preparation. |

CMSP Seminar (Joint ICTP/SISSA Statistical Physics): "Thermodynamic potential" for a class of non-equilibrium systems