Fields (all of them:)

[Marjan]

(1) Electromagnetic - photons
(2) Strong - gluons
(3) Weak - weak bosons
(4) Gravitational - gravitons
(5) Higgs - higgs bosons

We have unification under SM, called QFT. But how far that unification really goes?! Is it "only" a mathematical form of calculating all fields on the same procedure?

I am asking because we know that those fields are (quantum view) totaly different, we might say they have nothing in common. Different particles have different properties...


Can we talk about additional force -> Higgs force !? I think so. I guess nobody mention it, because particle has not been discovered yet (we hope on LHC 2008), but hey - nobody saw graviton either... ?!


Next interesting thing are fields itself. Let me just ask for starters if my view if correct. (i will start reading QFT shortly, but not just yet...).
In QFT perspective we can describe every field as static or dynamic. For example:
- static EM field: electric field is produced by still charge, it emits virtual photons
- dynamic EM field: EM field is produced by acceleration of charge, it emits real photons
- static gravity field: curved space-time is condition of still mass, it emits virtual gravitons
- dynamic gravity field: space-time disturbance motion is produced by acceleration of mass, it emits real gravitons
...
and analogous for every field! Is that view correct? I see certain beauty about it...

[Marjan]

Someone agrees with that? Is it too far? Maybe too clumsy written? :tongue:

[marlon]

(1) Electromagnetic - photons
(2) Strong - gluons
(3) Weak - weak bosons
(4) Gravitational - gravitons
(5) Higgs - higgs bosons

We have unification under SM, called QFT. But how far that unification really goes?! Is it "only" a mathematical form of calculating all fields on the same procedure?


QFT is the unification of QM and special relativity. This means that for example particles can be created out of nothing (vacuum) when enough energy is available. In QM energy and time are uncertain. In special relativity we know that E=mc². So suppose that we have a lot of energy, then we can say that this energy is mass via E=mc² and it therefore represents particles that exist for a very short while. Why very short ??? Well, because of the Heisenberg-uncertainty : product of uncertainty on E and t is constant. So if E is big, then ta has to be small. The created particles are also referred to as virtual particles. They can become real for a short while when enough energy is available as stated before. Virtual means that these particles can never be the end result of an interaction, they are just an intermediate step during some interaction.


I am asking because we know that those fields are (quantum view) totaly different, we might say they have nothing in common. Different particles have different properties...


What do you mean??? Besides there is something wrong with your classification.

1) electromagnetism mediated by photons
2) strong force mediated by gluons (and residual strong force is mediated by pions)
3) weak force mediated by intermediate vector bosons
4) gravitation mediated by gravitons

Gravitation is NOT described by COFT but by General Relativity. Attepmts to unify the two are string theory and LQG.


Can we talk about additional force -> Higgs force !? I think so. I guess nobody mention it, because particle has not been discovered yet (we hope on LHC 2008), but hey - nobody saw graviton either... ?!


The Higgs field is a property of the Higgs-mechanism. This field is always present in the vacuum-state like some kind of background. It makes sure that the vacuum is degenerated so that spontaneous breakdown of symmetry can occur yielding the mass of gauge-bosons like the vector bosons, and the particles like quarks. Only the photon does not interact with the Higgs-field because the U(1)-symmetry of EM is NEVER broken. This means that after the breakdown of symmetry, when nature has "chosen" one of the possible vacuum-states, this state still exhibits the U(1)-symmetry. Thus, a photon is always massless.

You can look at mass as the coupling constant of the Higgs-interaction.



Next interesting thing are fields itself. Let me just ask for starters if my view if correct. (i will start reading QFT shortly, but not just yet...).
In QFT perspective we can describe every field as static or dynamic. For example:
- static EM field: electric field is produced by still charge, it emits virtual photons
- dynamic EM field: EM field is produced by acceleration of charge, it emits real photons
- static gravity field: curved space-time is condition of still mass, it emits virtual gravitons
- dynamic gravity field: space-time disturbance motion is produced by acceleration of mass, it emits real gravitons
...
and analogous for every field! Is that view correct? I see certain beauty about it...

No, certainly NOT. First of all you cannot talk about curvature of spacetime in QFT. Gravity is not included in the standard model. Nevertheless, if you wanna do this, then you are gonna have to move to the string and LQG-forum.

I explained to you the difference between real and virtual photons and this distinction between static and dynamic field are not made in QFT. You are thinking to much in classical EM-terms...

For example : if two electrons interact they do so by interchanging virtual photons. The fact whether they move or not is irrelevant.


regards
marlon

[Norman]

First of all you cannot talk about curvature of spacetime in QFT

Hmm... I was wondering about this. I know there are issues that come up when you go from Minkowski to a curved spacetime, but I thought there were still some interesting calculations you can do on a curved spacetime. (this assumption is based completely on my school offering a class called "QFT on curved spacetime" and since I haven't taken it yet I am not completely sure)
Thanks,
Norm

[marlon]

Hmm... I was wondering about this. I know there are issues that come up when you go from Minkowski to a curved spacetime, but I thought there were still some interesting calculations you can do on a curved spacetime.

Curved spacetime is locally flat, so...


(this assumption is based completely on my school offering a class called "QFT on curved spacetime" and since I haven't taken it yet I am not completely sure)
Thanks,
Norm

No problem, the fact is that the curvature of spacetime due to present massess is negligible in QFT.

regards
marlon