IIT Kanpur

Fellow 2020 Physics


Inaugural Lectures by Fellows/Associates

Origin of Time Asymmetry and Friction in Multiscale Systems

Fundamental interactions are either fully or nearly symmetric under time reversal. But macroscopic phenomena typically exhibit a definite arrow of time. From the perspectives of statistical physics, the direction of time is towards increasing entropy. The speaker will describe how multiscale energy flux can also be used to determine arrow of time. In drivendissipative non-equilibrium systems forced at large scale, the energy typically flows from large scales to dissipative scales. This generic and multiscale process breaks time reversal symmetry and principle of detailed balance, thus can yield an arrow of time. He also proposes that conversion of large-scale coherence to small-scales decoherence could be treated as a dissipation mechanism for generic physical systems. In addition, he will discuss the equilibrium and nonequilibrium aspects of hydrodynamic equations. Turbulence will be used as a generic example to illustrate the above ideas.