Noun
(physics) A hypothetical particle that travels faster than the speed of light.
(physics) A flaw in a physical theory that predicts the existence of tachyons or similar paradoxical results. Compare with ghost.
Source: en.wiktionary.orgA charged tachyon traveling in a vacuum therefore undergoes a constant proper time acceleration and, by necessity, its worldline forms a hyperbola in space-time. Source: Internet
Cherenkov radiation A tachyon with an electric charge would lose energy as Cherenkov radiation citation —just as ordinary charged particles do when they exceed the local speed of light in a medium. Source: Internet
Fields with imaginary mass main In the paper that coined the term "tachyon", Gerald Feinberg studied Lorentz invariant quantum fields with imaginary mass. Source: Internet
However such tachyons are not possible due to the Sen conjecture, also known as tachyon condensation. Source: Internet
If the tachyon interacts with any other particles, it can also radiate Cherenkov energy into those particles. Source: Internet
In the case of a tachyon the real part of the mass is zero, and hence no concept of a particle can be attributed to it. Source: Internet