Tachyons are hypothetical particles with imaginary mass and they thus may move faster than light. However, their existence in a theory, indicates an unstable ground state.

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How does faster than light travel violate causality?

Let's say I have two planets that are one hundred thousand lightyears away from each other. I and my immortal friend on the other planet want to communicate, with a strong laser and a tachyon ...
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Status of experimental searches for tachyons?

Now that the dust has settled on the 2011 superluminal neutrino debacle at OPERA, I'm interested in understanding the current status of experimental searches for neutrinos. Although the OPERA claim ...
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Do tachyons move faster than light?

I am trying to understand whether or not tachyons travel faster than light. The linked Wikipedia page shows some seemingly contradictory statements, and they are confusing. For instance, the first ...
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Spinning Tachyons

In all examples that I know, tachyons are described by scalar fields. I was wondering why you can't have a tachyon with spin 1. If this spinning tachyon were to condense to a vacuum, the vacuum wouldn'...
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What if photons are not the fastest particles?

Einstein originally thought that special relativity was about light and how it always travelled at the same speed. Nowadays, we think that special relativity is about the idea that there is some ...
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How do tachyons violate causality?

Something moving faster than light should have imaginary mass, like photons have zero mass and thus travel at $c$. I have read this article of physicist E. C. George Sudarshan. He said taking mass ...
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Would the horizon of a black hole be different for a tachyon than for subluminal matter or photons?

One of the most useful black hole analogies I've seen imagines that space is "flowing" like a river into a black hole, and the point at which it flows in faster than c is the horizon. This analogy ...
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Are Electromagnetic Waves The Only Means of Transmitting Information?

We've been using EMF to transmit energy (information) for over a century. I was wondering is there any other way to send a message on long distances, even faster than EMF waves can travel? For example ...
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Can something travel faster than light if it has always been travelling faster than light?

I know there are zillions of questions about faster than light travel, but please hear me out. According to special relativity, it is impossible to accelerate something to the speed of light. However, ...
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Tachyon and Photons

Is there a particle called "tachyons" that can travel faster than light? If so, would Einstein's relativity be wrong? According to Einstein no particle can travel faster than light.
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What is the kinematics of a particle with complex mass?

particles with real-mass have time-like kinematics ($ds^2 > 0$). particles with zero-mass have light-like kinematics ($ds^2 = 0$). particles with imaginary-mass have space-like kinematics ($ds^2 &...
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Why does tachyon arise in bosonic string theory?

I am looking for precise mathematical and physical reasons which cause the presence of tachyon in bosonic string theory(specially closed bosonic string theory). Has it to do with the specific form of ...
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281 views

Is conservation of statistics logically independent of spin?

If the number of fermions is $n$, we expect the quantity $(-1)^n$ to be conserved, i.e., $n$ never changes between even and odd. This is known as conservation of statistics. In the normal context of ...
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What if a faster-than-light particle is found?

What will be the consequence (severe ones) on laws of physics if a particle that travels faster than light is discovered? I am looking for a more general answer so that a high school student would be ...
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Tachyonic antitelephone vs messaging through a wormhole

From the wikipedia article on tachyons: Most physicists think that faster-than-light particles cannot exist because they are not consistent with the known laws of physics.[3][5] If such particles ...
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Can pure-bosonic string theories exist in curved spacetime?

Question: Can there be a consistent non-supersymmetric pure-bosonic string theory in some curved spacetimes? Reason: Since fields with certain amount of negative mass can exist in curved spacetime (...
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Can tachyons escape the gravitational pull of a classical black hole?

Anything that crosses the event horizon of a black hole cannot escape the pull since it has crossed the Schwarzschild radius and thus, the escape velocity is greater than the speed of light, and since ...
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Do other particles besides scalars admit tachyonic solutions?

Do other particles besides scalars admit tachyonic solutions? For example fermions or gauge-boson tachyons? The picture in my head is that a tachyonic scalar simply rolls off some unstable potential ...
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Why does unbroken supersymmetry imply the absence of tachyons?

Just a quick question, same as in the title. I'm trying to understand stable D-branes.
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Imaginary masses

While watching this video, at around 5:00, the man mentions a certain type of particle having imaginary mass. He also says that these kind of particles can go faster then light. But how it is possible ...
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Relativistic mass and imaginary mass

The (relativistic) mass of an object measured by an observer in the $xyz$-frame is given by $$m = \frac{m_{rest}}{\sqrt{1 - \left(\frac{v}{c}\right)^2}}.$$ Mathematically $v$ could be greater than the ...
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Superluminal particles with causality

What kind of CLASSICAL theories would allow to true (non-apparent) superluminal particles (beyond speed of light, BSOL) agreeing with causality to exist? I mean, are causal superluminal classical ...
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General theorems on tachyon propagation?

I was reading the quite nice answer of QMechanic on the topic of compact support tachyon fields not propagating faster than light, but this case is a rather simple one, free scalar field in flat space....
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Closed timelike curves in the spin-2 gravity formalism

Let's say we take some topologically trivial CTC spacetime, like the Gödel metric: $$ds^2 = -dt^2 - 2e^{\sqrt{2}\Omega y} dt dx - \frac{1}{2}e^{\sqrt{2}\Omega y} dx^2 + dy^2 + dz^2$$ And then I ...
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Confinement of charged tachyons in AdS spacetime

It is well known that the negative cosmological constant of AdS spacetime can act like a confining potential. That is, in contrast to asymptotically flat spacetime, in an asymptotically AdS spacetime ...
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Gravitational coupling of tachyons

Can General Relativity stress-energy tensor be extended to include contributions from imaginary mass tachyons? what would be the expected gravitational coupling between tachyons and tardions?
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What is meant by open-string tachyon scattering amplitude?

It was said here that Veneziano derived: open-string tachyon scattering amplitude from principles of Regge theory and S-matrix theory and used the Euler beta-function to make all the critical ...
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Rate of spontaneous tachyon emission

It's not possible for an electron to emit or absorb a photon without the presence of a third particle such as an atomic nucleus; without the third particle, it's impossible for such a process to ...
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Does a theory exist with a symmetry between a tachyonic and non-tachyonic mass points which preserves the normal laws of the mechanic?

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 ...
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What're some criticisms of the paper “Six observations consistent with the electron neutrino being a tachyon with mass: mνe² = −0.11±0.016 eV²”?

Today I read about this paper making the case that neutrinos have imaginary mass and travel faster than light. I want to get excited, but I have no way to know how likely it is that this paper will be ...
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How could something have negative mass?

With all the theories on how Neutrinos apparently broke the light barrier, there was one theory someone told me of how neutrinos might have less than zero mass, but she didn't explain how this was ...
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Is there any theory in physics that might support the existence of tachyons?

According to Einstein, we all know that light is the fastest thing and it's impossible to beat it's speed. But isn't there a way to go around this? I read somewhere that tachyons gain speed per the ...
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Vertex operator for closed string tachyon

The problem related to this post, but my question is even more elementary. In p 101 of Polchinski's string theory vol I, it is stated Using the state-operator mapping, the vertex operator for the ...
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If tachyons were real, where would they originate from? [closed]

If the hypothetical tachyon existed, where would it possibly originate from? or is this question off the realms within the current state of physics. Also what are some ways physicist have tried to ...
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If tachyons exist, what would they do to spacetime?

Mass (Positive) bends space-time generating gravity. If Tachyons are supposed to have imaginary mass, what would they do to spacetime (if they do exist).
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Does the special theory of relativity form the foundation of modern physics?

Does the Special Theory of Relativity "form" the foundation of Modern Physics? My question is in reference to Geoff Brumfiel's Scientific American article "Particles Found to Travel Faster than Speed ...
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If tachyons existed, would we notice them?

In special relativity the space-time can be seen as a static four-dimensional picture that contains the entire past and the future of a flat universe. And the patterns in it are subject to several ...
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How exactly do superstrings reduce the number of dimensions in bosonic string theory from 26 to 10 and remove the tachyons?

In bosonic string theory, to obtain the photon as the first excited state, the ground state must have a negative mass (tachyon). By applying $1 + 2 + 3 + \cdots = -1/12$, it can be shown (in a ...
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The speed of tachyons

The other day I was wondering: When a tachyon is coming towards you faster than the speed of light, will you see it before it hits you? Then I thought of course not, since the light waves aren't ...
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Tachyons and Lorentz velocity transformation

In general, is it possible to apply the Lorentz velocity transformation to a tachyon? I have tried to do so but the results seemed very illogical. Here's my attempt: suppose an evil spaceship named ...
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Tachyonic field

i'm working on a paper about symmetron cosmology. symmetron is a scalar field that by its symmetry breaking can explain the dark energy. the action is: ans A , V are assumed to be: where M ...
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How is it that a tachyon is faster than $c$? [closed]

I remember reading that a tachyon is faster than light, but am still confused as to how and if they could exist in our universe?
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A question about the Weyl transformation for the vertex operator of the closed-string tachyon

I met a problem of derving the Weyl transformation on the closed-string tachyon, Eq. (3.6.8) in Polchinski's string theory, vol 1, p 103. Given the vertax operator of the closed-string tachyon $$...
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Would a tachyon be able to escape a black hole?

Or at least escape from a portion of the hole inside the photon horizon?
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What are the expression for Energy and Momentum of tachyons in terms of their 'rest mass'?

We examine the possibility of tachyons under the criteria that they form the energy momentum four vector that transforms according to Lorentz Transformations. Therefore, $E$$'$ $=\displaystyle\frac{...
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Is there absolute proof that an object cannot exceed the speed of light?

Have any known experiments ruled out travelling faster than the speed of light? Or is this just a widely accepted theory?
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970 views

Could Dark Matter be a manifestation of tachyons tunnelling between black holes? [closed]

Among the many Dark Matter candidates, I wondered if there are any along the lines of the title. The inner horizon of a black hole, with its mass inflation, and/or the high spacetime curvature, seems ...
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Tachyons and the light barrier

I read somewhere that if something breaks the light barrier, i.e. a tachyon, that it will take infinite energy to make it go slower than the speed of light. So, does that mean that the object will ...
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Learning about predicted interactions between black holes and tachyons

I'm a hobbyist reader/student looking for some reading material on the predicted effects of tachyons and black holes (or other ultra-high gravity wells). Are there any good links or references people ...
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Tomorrowland movie and tachyons? [duplicate]

Would be possible if tachyonic existed to send info to the past or see the future? since the tachyons according to special relativity could travel to the past? i have searched in wikipedia and the ...