Radha Balakrishnan

Radha Balakrishnan

Retired Professor
Theoretical Physics
22543177
radha @ imsc . res . in
RSA Annex
Research Interests: 
  •  Nonlinear Dynamics and applications to various  physical systems .
  • Solitons and exact solitary waves in Heisenberg magnetic chains, nonuniform media, elastic models, superfluid helium four, Bose-Einstein condensates, etc.
  • Geometric phases associated with nonlinear systems mappable to space curves, e.g., classical spin chains, twisted optical fibers, phase space trajectories.
  • Connections between nonlinearity and geometry in classical integrable systems.
  • Topological solitons and their knotted structure in 3D classical magnetic systems.
Education: 
  • B.Sc (Hons) Physics, University of Delhi, Delhi , India (1963)
  • M. Sc Physics, University of Delhi,  Delhi, India (1965)
  • M.S (Theoretical Physics), University of Rochester, Rochester N.Y. ,USA (1967)
  • Ph. D,  Brandeis University, Waltham MA, USA (1970)
Career History: 
  • 1970-1982:  Returned to India in 1970. Although not formally affiliated with any Institution during this period,  was active in research and published single author papers as well as collaborative papers in peer-reviewed journals. Some of these are given below, in the section `Selected publications'.
  • 1982-1985: CSIR Research Associate, Department of Theoretical Physics, University of Madras, Chennai, India.
  • 1985-1987: UGC Research Associate, Department of Theoretical Physics, University of Madras, Chennai, India.
  • 1987-2004: Faculty member at the Institute of Mathematical Sciences (IMSc), Chennai, India.
  • 2004-2014: After  retirement as Professor at IMSc, continued there as a CSIR Emeritus Scientist from 2004-2009, followed by a similar research grant funded by  DST from 2009-2014.
  • AWARDS AND HONOURS
  • Fulbright Scholar Award, USA (!984,1989,1995).
  • Senior Associateship Award (1992-1997) International Centre for Theoretical Physics (ICTP), Trieste, Italy.
  • Tamil Nadu Scientist Award (1999) from the Tamil Nadu State Council  for Science and Technology, in the field of Physical Sciences, for work on Geometric Aspects of Nonlinearity.
  • Professor Darshan Ranganathan Memorial Lecture Award (2005) from the Indian National Science Academy (INSA), for original and pioneering contributions in Nonlinear Dynamics.
Courses Taught: 
  • Nonlinear Dynamics
  • Statistical Mechanics
  • Electromagnetism
  • Condensed Matter Physics
Selected publications: 
  • Vacancies and helium-4 impurities in solid helium-3. Radha Balakrishnan and R. V. Lange, Phys. Rev. A 3, 496 (1971).
  • Mass-spin fluctuation waves in solid helium with isotopic impurities. Radha Balakrishnan and V. Balakrishnan, Phys. Rev. A 8, 2624 (1973).
  • Spin wave renormalization in the  Heisenberg ferromagnet II: Consistent linearized Green function theory for S=1/2. Radha Balakrishnan and V. Balakrishnan, Phys.  Rev. B 18, 1227 (1978).
  • Spin wave renormalization in the Heisenberg ferromagnet III: S =1 and S>1. Radha Balakrishnan, Phys. Rev. B 21, 2844 (1980).
  • On the inhomogeneous Heisenberg chain. Radha Balakrishnan, J. Phys. C 15, L 1305 (1982).
  • Soliton propagation in non-uniform media. Radha Balakrishnan,  Phys. Rev. A 32, 1144 (1985).
  • Nonlinear excitations on a quantum ferromagnetic chain. Radha Balakrishnan and A. R.Bishop, Phys. Rev. Lett. 55, 537 (1985).
  • Hydrodynamics of superfluid helium-4 in a pseudospin model. Radha Balakrishnan, R. Sridhar and R. Vasudevan, Phys. Rev. B 39, 174 (1989).
  • Nonlinear  dynamics of a quantum ferromagnetic chain:  Spin coherent state approach. Radha Balakrishnan and A. R. Bishop, Phys. Rev. B 40, 9194 (1989).
  • Geometric phase in the classical continuous antiferromagnetic Heisenberg spin chain. Radha Balakrishnan, A.R. Bishop and R. Dandoloff, Phys. Rev. Lett. 64, 2107 (1990).
  • Solitary wave propagation in superfluid helium-4 films. Radha Balakrishnan, Phys. Rev. B 42, 6153 (1990)
  • Anholonomy of a moving space curve and applications to classical magnetic chains. Radha Balakrishnan, A.R. Bishop and R. Dandoloff, Phys. Rev. B 47, 3108 (1993).
  • Transformation of general curve evolution to the modified Belavin-Polyakov equation. Radha Balakrishnan and R. Blumenfeld, J. Math. Phys. 38,  5878 (1997).
  • Energy structure of curved magnetic surfaces and its relationship with geometric phase. Radha Balakrishnan and A. Saxena, Phys. Rev. B 58, 14383 (1998).
  • The Schrodinger equation as a moving curve. Radha Balakrishnan and R. Dandoloff, Phys. Lett. A 260, 62 (1999).
  • New connections between moving curves and soliton equations.  S. Murugesh and Radha Balakrishnan, Phys. Lett. A  290, 81(2001)
  • Quantum effective potential, electron transport and conformons in biopolymers. R. Dandoloff and Radha Balakrishnan, J.Phys. A Math. Gen. 38, 6121 (2005).
  • Particle-hole asymmetry and brightening of solitons in a strongly repulsive Bose-Einstein condensate.
  • Radha Balakrishnan, Indubala I. Satija and C. W. Clark, Phys. Rev. Lett.103, 230403 (2009).
  • Quantum dynamics of solitons in strongly interacting systems on optical lattices. C.P. Rubbo, Indubala I Satija, W. P. Reinhardt, Radha Balakrishnan, Ana Maria Rey and Salvatore R Manmana, Phys. Rev. A 85, 053617 (2012).
  • Solitons in a hard-core bosonic system: Gross-Pitaevskii type and beyond.  Radha Balakrishnan and Indubala I Satija, Pramana 85, 1033 (2015).
  • Exact Hopfion vortices in a 3D Heisenberg ferromagnet. Radha Balakrishnan, R. Dandoloff and A. Saxena, Phys. Lett. A 480, 128975   (2023).
  • Twisted curve geometry underlying topological invariants. Radha Balakrishnan, R. Dandoloff and A. Saxena, Phys. Lett A 493, 129261 (2024).