Ennackal Chandy George Sudarshan (also known as E. C. G. Sudarshan; born 16 September 1931) is an Indian theoretical physicist and a professor at the University of Texas. Sudarshan has been credited with numerous contributions to the field of theoretical Physics including Optical coherence, Sudarshan-Glauber representation, V-A theory, Tachyons, Quantum Zeno effect, Open quantum system, Spin-statistics theorem, non-invariance groups, positive maps of density matrices, quantum computation among others. His contributions include also relations between east and west, philosophy and religion.

Early life

George Sudarshan was born in Pallam, Kerala, India. Despite being raised in a Syrian Christian family, he later left the religion in large part due to marrying Lalita, a Hindu and fellow student. They were married from 1954 to 1990 and have three sons, Alexander, Arvind (deceased) and Ashok.[1] He considers himself a "Vedantin Hindu".[2] He mentions disagreements with the Church's view on God and lack of spiritual experience as reasons why he left Christianity.[3][4]

He studied at CMS College Kottayam,[5] and graduated with honors from the Madras Christian College in 1951. He obtained his master's degree at the University of Madras in 1952. He moved to Tata Institute of Fundamental Research (TIFR) and worked there for a brief period with Homi Bhabha as well as others. Subsequently, he moved to University of Rochester in New York to work under Robert Marshak as a graduate student. In 1958, he received his Ph.D. degree from the University of Rochester. At this point he moved to Harvard University to join Julian Schwinger as a postdoctoral fellow.


Sudarshan has made significant contributions to several areas of physics. He was the originator (with Robert Marshak) of the V-A theory of the weak force (later propagated by Richard Feynman and Murray Gell-Mann), which eventually paved the way for the electroweak theory. Feynman acknowledged Sudarshan's contribution in 1963 stating that the V-A theory was discovered by Sudarshan and Marshak and publicized by Gell-Mann and himself.[6] He also developed a quantum representation of coherent light later known as Sudarshan–Glauber representation (for which controversially Glauber was awarded the 2005 Nobel prize in Physics ignoring Sudarshan's contributions).

Sudarshan's most significant work might be his contribution to the field of quantum optics. His theorem proves the equivalence of classical wave optics to quantum optics. The theorem makes use of the Sudarshan representation. This representation also predicts optical effects that are purely quantum, and cannot be explained classically. Sudarshan was also the first to propose the existence of tachyons, particles that travel faster than light.[7] He developed formalism called dynamical maps that is one of the most fundamental formalism to study the theory of open quantum system. He, in collaboration with Baidyanath Misra, also proposed the quantum Zeno effect.[8]

Sudarshan and collaborators initiated the "Quantum theory of charged-particle beam optics", by working out the focusing action of a magnetic quadrupole using the Dirac equation.[9][10]

He has taught at the Tata Institute of Fundamental Research (TIFR), University of Rochester, Syracuse University, and Harvard. From 1969 onwards, he has been a professor of Physics at The University of Texas at Austin and a senior professor at the Indian Institute of Science. He worked as the director of the Institute of Mathematical Sciences (IMSc), Chennai, India, for five years during the 1980s dividing his time between India and USA. During his tenure, he transformed it into a centre of excellence. He also met and held many discussions with philosopher J. Krishnamurti. He was felicitated on his 80th birthday, at IMSc Chennai[11] on 16th Sept, 2011. His areas of interest include elementary particle physics, quantum optics, quantum information, quantum field theory, gauge field theories, classical mechanics and foundations of physics. He is also deeply interested in Vedanta, on which he lectures frequently.

Controversy regarding Nobel Prize

Sudarshan began working on quantum optics at the University of Rochester in 1960. Two years later, Glauber criticized the use of classical electromagnetic theory in explaining optical fields, which surprised Sudarshan because he believed the theory provided accurate explanations. Sudarshan subsequently wrote a paper expressing his ideas and sent a preprint to Glauber. Glauber informed Sudarshan of similar results and asked to be acknowledged in the latter's paper, while criticizing Sudarshan in his own paper.[12] "Glauber criticized Sudarshan’s representation, but his own was unable to generate any of the typical quantum optics phenomena, hence he introduces what he calls a P-representation, which was Sudarshan’s representation by another name", wrote a physicist. "This representation, which had at first been scorned by Glauber, later becomes known as the Sudarshan–Glauber representation."

Sudarshan has been passed over for the Physics Nobel Prize on more than one occasion, leading to controversy in 2005 when several physicists wrote to the Swedish Academy, protesting that Sudarshan should have been awarded a share of the Prize for the Sudarshan diagonal representation (also known as Sudarshan–Glauber representation) in quantum optics, for which Roy J. Glauber won his share of the prize.[13] Sudarshan and others physicists sent a letter to the Nobel Committee claiming that the P representation had more contributions of "Sudarshan" than "Glauber". The letter goes on to say that Glauber criticized Sudarshan's theory—before renaming it the "P representation" and incorporating it into his own work. In an unpublished letter to The New York Times, Sudarshan calls the "Glauber–Sudarshan representation" a misnomer, adding that "literally all subsequent theoretic developments in the field of Quantum Optics make use of" Sudarshan's work— essentially, asserting that he had developed the breakthrough.[14]

In 2007, Sudarshan told the Hindustan Times, "The 2005 Nobel prize for Physics was awarded for my work, but I wasn't the one to get it. Each one of the discoveries that this Nobel was given for work based on my research."[15] Sudarshan also commented on not being selected for the 1979 Nobel, "Steven Weinberg, Sheldon Glashow and Abdus Salam built on work I had done as a 26-year-old student. If you give a prize for a building, shouldn’t the fellow who built the first floor be given the prize before those who built the second floor?"[15]



See also


  1. ^ W. Mark Richardson, ed. (2002). "George Sudarshan". Science and the Spiritual Quest: New Essays by Leading Scientists. Routledge. p. 243. ISBN 9780415257664. I was born in an Orthodox Christian family. I was very deeply immersed in it, and so by the age of seven I had read the entire Bible from Genesis to Revelation two or three times. I was not quite satisfied with Christianity, and gradually I got more and more involved with traditional Indian ideas. 
  2. ^ W. Mark Richardson, ed. (2002). "George Sudarshan". Science and the Spiritual Quest: New Essays by Leading Scientists. Routledge. p. 243. ISBN 9780415257664. I would now say I am a Vedantin, with these two religious and cultural streams mixed together. 
  3. ^ W. MssdasdASASKDNAJKDAJSBAkasnjbssadasdasdark Richardson, ed. (2002). "George Sudarshan". Science and the Spiritual Quest: New Essays by Leading Scientists. Routledge. p. 243. ISBN 9780415257664. PC: "Did your training as a scientist contribute at all to your growing dissatisfaction with the church?" GS: "No. It was simply that I found that the people who professed to practice were really not practicing. In other words, there was a great deal of show and not that much genuine spiritual experience. Further, a God “out there” did not fully satisfy me." 
  4. ^ W. Mark Richardson, ed. (2002). "George Sudarshan". Science and the Spiritual Quest: New Essays by Leading Scientists. Routledge. p. 250. ISBN 9780415257664. God is not an isolated event, something separate from the universe. God is the universe. 
  5. ^ "A proud moment for CMS College: Prof. Sudarshan delights all at his alma mater". The Hindu. Jul 5, 2008. Retrieved 5 April 2010. 
  6. ^ The beat of a different drum: The life and science of Richard Feynman by J. Mehra Clarendon Press Oxford (1994), p. 477, and references 29 and 40 therein
  7. ^ Time Machines: Time Travel in Physics, Metaphysics, and Science Fiction, p. 346, by Paul J. Nahin
  8. ^ Sudarshan, E. C. G.; Misra, B. (1977). "The Zeno's paradox in quantum theory". Journal of Mathematical Physics. 18 (4): 756–763. Bibcode:1977JMP....18..756M. doi:10.1063/1.523304. 
  9. ^ R. Jagannathan, R. Simon, E. C. G. Sudarshan and N. Mukunda, Quantum theory of magnetic electron lenses based on the Dirac equation, Physics Letters A, 134, 457–464 (1989).
  10. ^ R. Jagannathan and S. A. Khan, Quantum theory of the optics of charged particles, Advances in Imaging and Electron Physics, Editors: Peter W. Hawkes, B. Kazan and T. Mulvey, (Academic Press, Logo, San Diego, 1996), Vol. 97, 257-358 (1996).
  11. ^ "Sudarshan Fest" (PDF). 16 September 2011. 
  12. ^ "Physicist Sudarshan's omission questioned". The Hindu. December 2, 2005. 
  13. ^ Zhou, Lulu (December 6, 2005). "Scientists Question Nobel". The Harvard Crimson. Retrieved 2008-02-22. 
  14. ^ http://seedmagazine.com/content/article/first_runner-up/
  15. ^ a b Mehta, Neha (April 4, 2007). "Physicist cries foul over Nobel miss". Hindustan Times. Archived from the original on March 20, 2008. Retrieved 2008-02-22. 
  16. ^ "Padma Awards" (PDF). Ministry of Home Affairs, Government of India. 2015. Archived from the original (PDF) on November 15, 2014. Retrieved July 21, 2015. 


  • Phys. Rev. Lett. 10, 277-279 (1963)

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