It is commonly stated by U.S. physicists that Gerald Feinberg, of
Columbia University, originated the concept of the faster-than-light
particles he named "tachyons", but that is not correct. Here, for
the reader's edification, is the truth of the matter.

Exerpt from online article "Theory of Tachyons: Faster than Light
Propagation", about E.C. George Sudarshan, Professor of Physics,
University of Texas at Austin.
____________

In the summer of 1958 when Sudarshan was at the University of
Rochester, someone asked him about what happens to energy and
momentum when a particle travels faster than light.
Sudarshan saw that energy and momentum could be made real by taking
rest mass to be imaginary for such particles.
The second difficulty of the apparent traveling "backward in time" of
such a particle was solved by the interchange of the emission and
absorption of the particle. Along with a graduate student, V. K.
Deshpande, Sudarshan wrote a short paper and sent it to Physical
Review Letters. It came back from a referee who rejected it, saying
it was incorrect. Sudarshan requested a second referee who said that
the results of the paper were correct, but it was all well known!
A third referee stated that he had "read both the previous referee
reports and he agreed with both of them"!
About two years later, after Sudarshan joined the University of
Rochester faculty, his colleague O.M.P. Bilaniuk offered to rewrite
the paper and get it published. He did it and they published it in
American Journal of Physics. It attracted a lot of attention and
several letters to Physics Today.

To make a quantum theory one had to quantize a scalar field with
imaginary mass. Dhar and Sudarshan completed this in the spring of
1968. (By this time Feinberg at Columbia published a paper with all
Sudarshan's results, without acknowledgement to him).
Feinberg's work contained essential inconsistencies, but it supplied
the name "tachyon" for these particles. Arons and Sudarshan corrected
the mistakes in Feinberg's work and carried out the correct
quantization of tachyons.

The quantum theory of tachyons contained the reinterpretation
principle; and they could have either spin 0 or "continous spin" and
could obey either Bose or Fermi statistics.
The quantum field theory leads to a tachyon cloud of virtual
particles coupled to a tachyon field.
Tachyons could manifest themselves as resonances in momentum transfer
in particle collisions. Various other aspects are treated in other
papers including many by Recami.
To date, no tachyons have been detected. However, tachyons arise
naturally in string theories but are suppressed or ignored. ...

____________


Note that there are a significant number of important print sources
cited at the end of the above online article, which can be found at
http://www.ph.utexas.edu/fogs/sudarshan_tachyons.html

For more on Professor Sudarshan's accomplishments, go to
http://www.ph.utexas.edu/fogs/index.html

The foregoing information was copied and pasted without the
permission of the originators.
It was gleaned from an online Symposium, from the University of Texas
at Austin, entitled
"Sudarshan: Seven Science Quests".
The URL is as follows;
http://www.ph.utexas.edu/fogs/symposium/index.html

Readers here are invited to post comments, as desired.