Re: Exotic Physics
To me, anything becoming tachyonic would seem to be exotic.
Here, apparently, "tachyonic" just means "having imaginary mass"1. And that really just means that its energy is not in a stable equilibrium (it's at a local maximum rather than a local minimum), thus spontaneous symmetry breaking2 occurs, and it moves to a lower energy state. This makes it no longer tachyonic, a process called "condensation" (because the lower energy becomes a condensate of new particles).
So it's not "exotic" in the sense of "not happening very often"; or in the sense of "gosh that's pretty weird" (relative to other stuff that happens at the quantum level); or in the sense of "the mathematics are bizarre" (because as it turns out they're not); or in the sense used in the article, which is "different from the Standard Model". It's perfectly in keeping with the SM, as I understand it.
Of course, you can still find it "exotic" in a subjective sense.
1A non-tachyonic field usually has complex mass, where the real part corresponds to rest mass (I think) and the imaginary part to decay rate. At least that's my understanding from browsing some of this stuff. I may be wildly incorrect. But the point is "imaginary mass" here just means "the real part is zero". This also means the field doesn't have any particle-like nature, apparently, until it condenses and becomes non-tachyonic.
2The standard analogy here is a ball balanced on top of a perfectly symmetrical hill. Any perturbation will cause the ball to roll down the hill in some direction, which breaks the symmetry.
Biting the hand that feeds IT
