Research interests and activities:

SOFT-MATTER AND NONEQUILIBRIUM STATISTICAL PHYSICS: the statistical mechanics of sedimentation; dynamics and rheological chaos in surfactant solutions; theory and experiments on ordered nonequilibrium steady states in agitated monolayers of granular rods
THE MECHANICS OF LIVING MATTER: statistical hydrodynamics of self-driven organisms --- fish, bacteria, cell-membranes with pumps, motors, filaments, and ATP; the rheology of the living cell.

Recent publications and preprints

2010

• A Dynamic Renormalization Group Study of Active Nematics Shradha Mishra, R Aditi Simha, Sriram Ramaswamy (J. Stat. Mech.(2010) P02003)
(arxiv.org/0912.2283)
• Nonequilibrium noise in electrophoresis: the microion wind, Suropriya Saha, Sriram Ramaswamy (arxiv.org/0907.0469)

2009

• Dynamics of a stiff biopolymer in an actively contractile background: buckling, stiffening and negative dissipation, N Kikuchi, A Ehrlicher, D Koch, J A Kaes, S Ramaswamy, M Rao [PNAS 106 (2009) 19776-19779] (arxiv.org/0901.4126)
• Universality Class of the Reversible-Irreversible Transition in Sheared Suspensions, G I Menon, S Ramaswamy, Phys Rev E 79 (2009) 061108 (arxiv.org/0801.3881)
• Instabilities and waves in thin films of living fluids, Sumithra Sankararaman and Sriram Ramaswamy, Phys Rev Lett 102 (2009) 118107 (arxiv.org/0809.4918)

2008

• Exact solution of a Brownian inchworm model for self-propulsion, A. Baule, K. Vijay Kumar and S. Ramaswamy, J. Stat. Mech. (2008) P11008 (arxiv.org/0903.1572)
• Active elastic dimers: self-propulsion and current reversal on a featureless track, K. Vijay Kumar, S. Ramaswamy and M. Rao, Phys Rev E (Rapid Comm.) 77 (2008) 020102 R (arxiv.org/0708.1802)

2007

• Active-filament hydrodynamics: instabilities, boundary conditions and rheology, S. Ramaswamy and M. Rao, New Journal of Physics 9 (2007) 423 (Focus Issue on Physics of the Cytoskeleton).
• Perspectives on the mode-coupling approximation for the dynamics of interacting Brownian particles, A. Basu and S. Ramaswamy, J. Stat. Mech. (2007) P11003.
• Long-lived giant number fluctuations in a swarming granular nematic, V. Narayan, S. Ramaswamy, N. Menon, Science 317 (2007) 105; (cond-mat/0612020)
• Shear-flow-induced isotropic to nematic transition in a suspension of active filaments, S. Muhuri, M. Rao and S. Ramaswamy, Europhys Lett 78 (2007) 48002; (cond-mat/0610025)
• Superdiffusion of concentration in wormlike-micelle solutions, Rajesh Ganapathy, A.K. Sood, and Sriram Ramaswamy, Europhys Lett 77 (2007) 18007.

2006

• Active nematics are intrinsically phase-separated, Shradha Mishra and Sriram Ramaswamy, Phys Rev Lett 97 (2006) 090602 (cond-mat/0603051)
• Brownian-drag induced particle current in a model colloidal system, Moumita Das, Sriram Ramaswamy, A.K. Sood, and G. Ananthakrishna, Phys. Rev. E 73 (2006) 061409
• Do current-density nonlinearities cut off the glass transition? M. E. Cates and S. Ramaswamy, Phys. Rev. Lett. 96 (2006) 135701 (cond-mat/0511260)
• Vijay Narayan, Narayanan Menon and Sriram Ramaswamy, Nonequilibrium steady states in a vibrated-rod monolayer: tetratic, nematic and smectic correlations, J. Stat. Mech. (2006) P01005. (cond-mat/0510082)
• The mechanics of active matter: Broken-symmetry hydrodynamics of motile particles and granular layers, S. Ramaswamy and R.A. Simha, Solid State Communications 139 (2006) 617-622
• Rheological chaos in wormlike micelles and nematic hydrodynamics Moumita Das, Ranjini Bandyopadhyay, Buddhapriya Chakrabarti, Chandan Dasgupta, Sriram Ramaswamy and Ajay Sood, in Molecular Gels: Materials with Self-Assembled Fibrillar Networks, Richard G. Weiss and Pierre Terech (editors), Kluwer, Amsterdam (2006).

2005

• Superdiffusion of concentration in wormlike micelle solutions, by Rajesh Ganapathy, A.K. Sood, and Sriram Ramaswamy (submitted)
• Hydrodynamics and phases of flocks, J. Toner, Y. Tu and S. Ramaswamy, Ann. Phys. 318 (2005) 170
• Routes to spatiotemporal chaos in the rheology of nematogenic fluids B. Chakrabarti, M. Das, C. Dasgupta, S. Ramaswamy, A.K. Sood Phys. Rev. E 71 (2005) 021707 (cond-mat/0408282)

  2004

• Spatiotemporal rheochaos in nematic hydrodynamics B. Chakrabarti, M. Das, C. Dasgupta, S. Ramaswamy, A.K. Sood Phys Rev Lett 92 (2004) 055501 (cond-mat/0311101)
• Rheology of active-particle suspensions, Y. Hatwalne, S. Ramaswamy, M. Rao and R. A. Simha, Phys Rev Lett 92 (2004) 118101 (cond-mat/0308529)
• Flow-induced current and voltage generation in carbon nanotubes, S. Ghosh, A.K. Sood, S. Ramaswamy, N. Kumar, Phys. Rev. B 70 (2004) 205423 (cond-mat/0407803)

  2003

• The segregation instability of a sheared suspension film, R. Govindarajan, P.R. Nott and S. Ramaswamy, submitted to Phys. Fluids (2003) (cond-mat/0312189)
• Rheology of disordered lamellar phases, S. Sukumaran, S. Ramaswamy, P.R. Nott and V. Kumaran, submitted to Phys Rev Lett (2003).
• Collective stochastic resonance in shear-induced melting of sliding bilayers M. Das, G. Ananthakrishna and S. Ramaswamy, Phys. Rev. E 68, 061402 (2003) (cond-mat/0307519)
• Active nematics on a substrate: giant number fluctuations and long-time tails, S. Ramaswamy, R.A. Simha and J. Toner, Europhys.Lett. 62 (2003) 196-202 (cond-mat/0208573)

  2002

• Melting-freezing cycles in a relatively sheared pair of crystalline monolayers, M. Das, S. Ramaswamy and G. Ananthakrishna, Europhys Lett 60 (2002) 636-642 (cond-mat/0205030)
• Ratchet for energy transport between identical reservoirs, S. Das, O. Narayan and S. Ramaswamy, Phys Rev E (Rapid Comm) 66, 050103 (2002) (cond-mat/0206372)
• Anomalous heat conduction in one dimensional momentum-conserving systems, O. Narayan and S. Ramaswamy, Phys Rev Lett 89 (2002) 200601 (cond-mat/0205295)
• Driven Heisenberg Magnets: Nonequilibrium Criticality, Spatiotemporal Chaos and Control, J. Das, M. Rao and S. Ramaswamy, Europhys. Lett., 60 (2002) 418-424 (cond-mat/0104566)
• Stripes in sheared non-brownian suspensions with a free surface, R. Govindarajan, P.R. Nott and S. Ramaswamy, Proc. Statphys Kolkata 2002 (Physica A, in press).
• Phase Diagram of a Two-Species Lattice Model with a Linear Instability, S. Ramaswamy, M. Barma, D. Das, and A. Basu (Proc. Discussion Meeting on Slow Dynamics and Freezing, Jawaharlal Nehru University), Phase Transitions B 75 (2002) 363-375
• Hydrodynamic fluctuations and instabilities in ordered suspensions of self-propelled particles, R. A. Simha and S. Ramaswamy Phys Rev Lett 89 (2002) 058101 (pdf file of paper)
• Statistical hydrodynamics of ordered suspensions of self-propelled particles: waves, giant number fluctuations and instabilities, R.A. Simha and S. Ramaswamy (Proc. STATPHYS21) Physica A 306 (2002) 262-269 (pdf file of paper)

  2001

• Theory of Suspension Segregation in Partially Filled Horizontal Rotating Cylinders, R. Govindarajan, P.R. Nott and Sriram Ramaswamy, Phys. Fluids (Lett.) 13 (2001) 3517-3520 (pdf file of paper) (cond-mat/0109428)
• The physics of active membranes, S. Ramaswamy and Madan Rao, C.R. Acad. Sci. Paris (special issue on Physics at the Scale of the Cell) t. 2, Ser. IV, 817-839 (2001).
• Issues in the statistical mechanics of steady sedimentation, S. Ramaswamy, Adv. Phys. 50 (2001) 297-341. (pdf file of paper)
• Weak and strong dynamic scaling in a one-dimensional driven coupled-field model: Effects of kinematic waves, D. Das, A. Basu, M. Barma and S. Ramaswamy, Phys. Rev. E 64 (2001) 021402 (pdf file of paper)
• Active Membrane Fluctuations Studied by Micropipet Aspiration, J-B. Manneville, P. Bassereau, S. Ramaswamy, J. Prost, Phys. Rev. E 64 (2001) 021908 (pdf file of paper)

  2000

• Nonequilibrium noise, steady states, and instabilities in membranes with active proteins
  S. Ramaswamy, J. Toner, and J. Prost, Phys. Rev. Lett. 84 (2000) 3494-3497 (pdf file of paper)
• Strong phase separation in a model for sedimenting lattices
  R. Lahiri, M. Barma, and S. Ramaswamy
  Phys. Rev. E 61 (2000) 1648 (pdf file of paper)
• Inequivalence of ensembles in a driven diffusive system
  M. Acharyya, A. Basu, R. Pandit, and S. Ramaswamy
  Phys. Rev. E 61 (2000) 1139 (pdf file of paper)

  1999

• Travelling waves in a drifting flux lattice
  R. Aditi Simha and S. Ramaswamy
  Phys. Rev. Lett 83 (1999) 3285 (pdf file of paper)
• Structure and rheology of the defect-gel states of pure and particle-dispersed lyotropic lamellar phases,
  G. Basappa, Suneel, V. Kumaran, P.R. Nott, S. Ramaswamy, V.M. Naik and D. Rout
  Eur. Phys. Jour. B 12 (1999) 269-276. (pdf file of paper)
• Mean magnetic field and noise cross-correlation in magnetohydrodynamic turbulence: results from a one-dimensional model,
  A. Basu, J.K. Bhattacharjee and S. Ramaswamy,
  Eur. Phys. Jour. B 9 (1999) 725-730 (pdf file of paper)

  1998

• Screened and unscreened phases in sedimenting suspensions,
  A. Levine, S. Ramaswamy, E. Frey and R. Bruinsma,
  Phys. Rev. Lett. 81, 5944-5947 (1998) (pdf file of paper)

  1997

• (i) Self-diffusion of colloids at freezing;
  (ii) Shear-enhanced diffusion in colloids;
  (iii) Excess dissipation in dense emulsions;
  three chapters in Theoretical Challenges in the Dynamics of Complex Fluids
  (lectures in a NATO Advanced Study Institute), Ed. T C B McLeish, Kluwer 1997 (three .ps files tarred into a single file)
• Are steadily moving crystals unstable? R. Lahiri and S. Ramaswamy, Phys. Rev. Lett. 79, 1150-1153 (1997) (pdf file of paper)