Existence of Tachyons is not yet established. But If it establish it would be actual particles with imaginary mass energy and negative time. Further they will loss energy with increase in time.Weren't tachyons only instabilities in fields and not actual particles?
I don't see where it has been accepted. If a referee, I would probably not accept it. There's very little new here - Ehrlich has been going on about this for more than a decade.
It is absolutely true that the neutrino mass experiments that measure m-squared allow it to go negative in their fits. To do otherwise biases the result high. It is also true that these measurements come out negative - the PDG average is -0.6 +/- 1.9 and the statement "Given troubling systematics which result in improbably negative estimators of m2 in many experiments we use only Kraus 05 and Lobashev 99 (I think they mean Aseev 11) for our average." They then go on to comment on exactly how these two measurements are better than the ones they supersede and how the systematics are better controlled.
As for the cosmological measurements, I am not at all surprised that if one replaces constants in the calculation that the results shift, nor that with the right set, the mass squared can go negative. However, what I don't see is a good argument that these are the right constants to use, apart from the fact that they give interesting conclusions.
For me to believe neutrinos are tachyons, I would prefer to see one strong piece of evidence rather than a lot of weak ones.
I read it here:Existence of Tachyons is not yet established. But If it establish it would be actual particles with imaginary mass energy and negative time. Further they will loss energy with increase in time.
(From this page.)Wikipedia said:In the 1967 paper that coined the term,[1] Feinberg proposed that tachyonic particles could be quanta of a quantum field with negative squared mass. However, it was soon realized that excitations of such imaginary mass fields do not in fact propagate faster than light,[5] and instead represent an instability known as tachyon condensation.[3] Nevertheless, negative squared mass fields are commonly referred to as "tachyons",[6] and in fact have come to play an important role in modern physics.
Do they want to violate special relativity?
Weren't tachyons only instabilities in fields and not actual particles?
I would prefer to see one strong piece of evidence rather than a lot of weak ones.
Then they need really strong evidence. Especially in a field where 2-3 sigma effects come and go all the time and even 5 sigma effects can disappear.Yes.
Thanks for that. But this only treats scalar tachyons which isn't useful when we talk about neutrinos. I checked some QFT texts but non of them treat tachyons(which isn't surprising). Not much was on internet too. Can you suggest a text that treats tachyons?(Specially fermionic ones)This Usenet Physics FAQ article has a good discussion of tachyons:
http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/tachyons.html
this only treats scalar tachyons
Can you suggest a text that treats tachyons?(Specially fermionic ones)
The original paper by Bilaniuk and Sudarshan (referenced in the article) turns out to be available online:
https://www.uam.es/personal_pdi/ciencias/jcuevas/Teaching/Taquiones.pdf
It doesn't explicitly discuss solutions of equations of motion the way the Usenet article does; however, the considerations raised in the paper appear to me to apply to any tachyonic particle, regardless of spin.
Google shows a number of articles that appear to discuss tachyonic solutions of the Dirac equation. AFAIK the general solution properties of the Klein-Gordon equation that are discussed in the Usenet article should also hold for the Dirac and Maxwell equations, since both of those are known to be consistent with relativistic causality.
localized tachyon disturbances are subluminal and superluminal disturbances are nonlocal.
I think whether or not the following sentence is true, depends to a high extent on the equation that the particle obeys.
If neutrinos are Tachyons, wouldn't the neutrinos from SN1987A have arrived here much earlier?
Is this addressed in the paper?
If neutrinos are Tachyons, wouldn't the neutrinos from SN1987A have arrived here much earlier?
Not if their energy was large enough for their velocity to be sufficiently close to the speed of light.
Isn't it if their energy were small enough for their velocity to be sufficiently close to the speed of light? As a tachyon gains energy, it slows down.
No. The limit is determined by the dispersion in arrival times - we don't have an absolute measurement of when SN1987A happened. That limit can be expressed as the |m2| < few eV2.
