infinte fields and massless particles

[36grit]

I understand that massless particles exist in infinite fields. I am wondering if there is a chart or a list of particles that share this infinite field.

Also, I was wondering if an infinite field would require an ifinite rate of expansion?

 

 

 

[DrRocket]

I understand that massless particles exist in infinite fields. I am wondering if there is a chart or a list of particles that share this infinite field.

Also, I was wondering if an infinite field would require an ifinite rate of expansion?

 

 

 

 

You need to be a bit more clear as to what fields you are talking about. Most theories that involve fields are modeled on ordinary Euclidean space, which may be what you mean by infinite. If so that has nothing to do with expansion.

 

Generally when people speak of "expansion" they are talking about cosmology and the expansion of space, which relates to a model based on general relativity.

 

Current quantum field theories are incompatible with general relativity.

 

So perhaps your question relates to some unified theory that would include quantum gravity. No such theory yet exists, but it is an active area of research. Don't hold your breath. It has been an active area of research for a long time.

[ajb]

I understand that massless particles exist in infinite fields.

 

 

I don't understand what you mean by this.

[MigL]

If I understood you correctly, yes, fields of infinite range like an EM field, are propagated by massless carriers like photons. Short, limited range fields like the Weak force are propagated by massive particles, the +/-W and Z. At Weak scale energies, before the scalar field ( Higgs??) breaks symmetry, the combined electroweak force is propagated by photons and massless +/-W and Z particles ( see Weinberg, Salam and Glashow ).

 

The Strong force is a different beast as it is asymptotic. The force is effectively zero up to a certain distance at which point it starts increasing with distance. But maybe someone else can give you the particulars as gluons and quarks have too many properties ( up, down, charm, strange, colour etc. ) for me to remember.

 

Gravity is also an infinite range field, but our best theory of gravity, GR, makes no predictions of carrier particles. Quantum gravity theories would make a prediction one way or another,but we don't have one yet.

 

Massive gravitons have been postulated, but so have monopoles and unicorns.

 

I believe that accounts for the four fundamental forces, but I also don't understand the relevance of expansion.

[ajb]

Massive gravitons have been postulated, but so have monopoles and unicorns.

 

Very poor analogy. Gravitons and monopoles are predicted by the theories, there is some mathematical basis for thinking these things may exist. Unicorns are just in the human mind, no reason to believe that they might exist.

[MigL]

Maybe so, but The theories that predict gravitons are incomplete and certainly GR doesn't. And even if predicted at the Planck scale energy at which gravitons would be observed, we might need a collider about 10 light years in diameter to supply the required energies, making the likelyhood of actually seeing one about as likely as a unicorn. As for monopoles, doesn't Guth's inflation do away with the solitons ( monopoles ) created at domain boundaries ?

[ajb]

Maybe so, but The theories that predict gravitons are incomplete and certainly GR doesn't.

 

This is going to depend on what you mean by GR predicting or not predicting gravitons.

 

If one wants to treat perturtbative quantum general relativity as an effective theory then I would say that GR does predict gravitons. One then assumes we can complete the theory and define a perturbative theory of quantum gravity, just one does not know exactly what that is. The moto is "gravitons are to the metric what photons are to the electromagnetic field".

 

However, it maybe the case that a quantum theory of gravity is not a theory of gravitons and there is no perturbative definition of quantum gravity. For instance quantum general relativity may be asymptotically safe. So from this point of view GR does not predict gravitons.

 

 

 

And even if predicted at the Planck scale energy at which gravitons would be observed, we might need a collider about 10 light years in diameter to supply the required energies, making the likelyhood of actually seeing one about as likely as a unicorn.

 

Sure, it maybe very difficult to detect gravitons but this is no reason to rule them out. Lack of evidence is not evidence of the graviton not being realised in nature. As I said, I see no reason to predict that unicorns exist.

 

As for monopoles, doesn't Guth's inflation do away with the solitons ( monopoles ) created at domain boundaries ?

 

Inflation dilutes the monopole density so that they are not cosmologically significant. A few per horizon would be fine. So they maybe very rare in nature, but not necessarily completely absent.

[36grit]

I guess what I'm looking for is chart of massless particles. Both ones discovered and predicted by scientifically accepted standard models.

 

I think we have a lot to learn about gravity, distance, and time. I see distance itself as a force field. Distantron density is the defining feature of a time dialation. If distance is something then it is possible that distance particles should exist with noting inbetween them. This would affect the time attribute of a field. The more nothing that you have inbetween the distance particles the faster you could go from here to there. I don't think massless particles require distance to exist within their wave function field. Like I said, We are just now scratching the surface of the microverse and the things that might have existed before the universe.

[J.C.MacSwell]

Very poor analogy. Gravitons and monopoles are predicted by the theories, there is some mathematical basis for thinking these things may exist. Unicorns are just in the human mind, no reason to believe that they might exist.

 

Especially after that Ark fiasco!