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Does a theory exist with a symmetry, which mirrors the tachyon mass points to non-tachyon mass points and vice versa?

I think, it would be very beautiful, despite that there are strong theoretical arguments (and experimental results) that they don't exist.

peterh
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  • This is all very hypothetical. You appear to be making wild speculations without any justification. – sammy gerbil Jun 13 '16 at 00:01
  • @sammygerbil Maybe you could look after the other questions about the tachyons to see what is the accepted level of speculations here. Further, I am asking for the existence of an already existing theory and didn't made any statement. – peterh Jun 13 '16 at 00:05
  • why would a tachyon violate the conservation of center of mass? their mass is imaginary, so the answer does not seem that obvious? could you expand your intuition or calculation? –  Jun 13 '16 at 00:14
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    @Wolphramjonny I think it is clearly visible that it is against newtons second law (consider a collision of two tachyonic mass points with different masses, what will happen to their center of mass?). I didn't calculated it too deeply, but I can if you wish. But, it is not the essence of this question, the essence if that does a symmetry, i.e. a mirror operation exist, which would exchange tachyonic mass points to non-tachyionic ones and vice versa. – peterh Jun 13 '16 at 00:20
  • @Wolphramjonny I removed this part of the question, how is it now? – peterh Jun 13 '16 at 00:22
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    oh, I see it, thanks! you didnd have to remove anything, I am not a dictator! just asking about a subject I do not dominate –  Jun 13 '16 at 00:22
  • It is actually a good point –  Jun 13 '16 at 00:34
  • Peter, I apologise. The only substantial question is "Status of experimental searches for tachyons?" http://physics.stackexchange.com/q/63297. The answer appears to be "nil" or at best "dubious" (there are some unexplained anomalies). Nevertheless, questions about tachyons appear to be tolerated on PSE (there is an official tag), and we (I especially) should be more tolerant of theories which may yet prove true, when there is so much else at present (eg dark matter/energy) that has no agreed explanation. I note that you have also removed the parts of your question which I objected to. – sammy gerbil Jun 13 '16 at 00:37
  • @sammygerbil I didn't asked about the tachyons as existing things, I asked about them as theoretical constructions. Btw, as I know, a world from only tachyons would be consistent, and they often appear in different QFT things to be considered so-so mainstream (not their existence, but their role - as hypotethical consgtructions - everywhere on physics papers). See, for example this. That is absolute o.k. that you don't really like questions about this. – peterh Jun 13 '16 at 06:53
  • @sammygerbil Many physicists also doesn't like that and I can accept at. Honestly, knowing the fact that even the existence of the (Schw) black holes isn't based on very strong experimental results, I accept it is maybe too early to talk about the wormhole-like aspects of the Kerr metric. – peterh Jun 13 '16 at 06:56
  • @sammygerbil Btw, there are also things which are considered very-very mainstream, for example GUT particles around 1e+16 GeV mixing leptons and quarks, I think they are at least hyphotethical things as the tachyons. (Ok, I admit their existence is at least probable on the current experiments, while the tachyons' is very improbable). – peterh Jun 13 '16 at 07:04
  • Is the mass of the tachyon -ve or imaginary? Or is there no difference? – sammy gerbil Jun 13 '16 at 10:53
  • Yes there is far too much speculation in modern physics, IMO. The problem of asking questions about speculative theories is that there are no right or wrong answers, only opinions. You ask "Does a symmetry exist?" but without a clear statement of the tachyon theory this cannot be answered. There is no agreed tachyon theory. Like string theory, there are still a lot of loose ends. – sammy gerbil Jun 13 '16 at 11:06
  • @sammygerbil Afaik questions like "does a theory already exists" are not opinion-based. – peterh Jun 13 '16 at 13:42
  • Your question was not "Does a theory exist?" but "Does a symmetry exist?" That can only be answered by reference to a theory, but you have not identified such a theory. – sammy gerbil Jun 13 '16 at 13:55
  • @sammygerbil Ok, it was the easiest to fix. – peterh Jun 13 '16 at 13:59
  • In 1+1 dimensions, you could reflect spacetime in a null line, to map tachyons (spacelike worldlines) to tardyons (timelike worldlines) and vice versa. – Mitchell Porter Jun 02 '17 at 00:05
  • @MitchellPorter Thanks! I was thinking on such a symmetry, where the tachyons live in a world with 1 space and 3 time dimensions. Thus, there would be a tachyonic 1+3 Universe and our bradyonic 3+1. The details are unclear also for me, but maybe there are theories playing with this. I think it could be useful to explain many currently unknown phenomena (dark energy, for example). – peterh Jun 02 '17 at 00:10
  • You might need a 3+3 space-time (use 2+2 and 1+1 for practice). But although multi-time theories have been considered, I haven't seen any such theory which has tachyons, in the old sense of Feinberg, faster than light. In today's mainstream, tachyon means imaginary mass, and is considered an artefact of defining particle excitations around the wrong minimum of a field... If FTL theories can be defined at all, there will be extra constraints on consistency, from the need to avoid time-loop paradoxes (CTCs)... Also try googling "bradyon tachyon symmetry" and "tachyon bradyon symmetry". – Mitchell Porter Jun 12 '17 at 07:09

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