TITLE : Superdiffusion and antidiffusion in an aligned active suspension

ABSTRACT :

We show that active-particle suspensions in intrinsically anisotropic fluids are governed by new universality classes. In the homogeneous state we show that the concentration relaxes superdiffusively. Increasing activity leads to phase separation through a diffusive instability driven by hydrodynamic flow. We suggest several experimental settings to test our predictions; our numerical studies on Brownian particles coupled to active fluid flow confirm the superdiffusion. This work was done jointly with LP Dadhichi, Suvendra Sahoo and K Vijay Kumar, and is summarised in arXiv:2510.00740

ABOUT THE SPEAKER :

Theoretician with broad interests in nonequilibrium, soft-matter and biological physics; laid down the defining principles of the field known as Active Matter, the study of materials whose constituents, such as cells in a tissue, continually convert a free-energy supply into work.

Career: At IISc Physics since 1986 (currently Honorary Professor); also Endowed Visiting Professor, ICTS-TIFR and Distinguished Visiting Professor, IIT Bombay; Former Director, TIFR Hyderabad (From 2012 to 2016); Postdoc: U Pennsylvania 1983-86. Education: PhD (U Chicago) 1983, BS (high hons, U Maryland) 1977, Higher Secondary (Modern School, Barakhamba Road, New Delhi) 1973.

Selected awards & honours: Shanti Swarup Bhatnagar Prize (2000), Infosys Prize (2011); J C Bose Fellow since 2007; Fellow, INSA, IAS, NASI; elected FRS 2016 and International Member, US National Academy of Sciences 2025.

MEETING DETAILS :

Joining Link: https://meet.google.com/toe-dxzc-afd

Speaker: Prof. Sriram Ramaswamy (Honorary Professor and J C Bose National Fellow, Department of Physics, Indian Institute of Science Bengaluru ; Endowed Visiting Professor, ICTS-TIFR, Bengaluru ; Distinguished Visiting Professor, IIT Bombay)

Venue: A4-Conference Room, South Campus, IIT Mandi

Date and Time: October 30, 2025, Thursday at 5:00 PM