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6
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2answers
219 views

Do virtual photons have a frequency?

Real photons do have frequencies, which is directly related to its energy. So, can virtual photons that take part in EM interactions have frequencies too? When my hand is pressed up against a glass ...
3
votes
2answers
126 views

Electromagnetic reaction force?

The classical (retarded) Lienard-Wiechert scalar and vector potentials describe the electromagnetic field due to an arbitrarily moving electric point charge. Thus given the motion of electron $A$ one ...
2
votes
1answer
70 views

What equation describes virtual photons becoming real photons?

From my understanding, virtual particles are actually "disturbances" between two elementary particle interactions and appear during cross sections of these interactions. What equation(s) describe this ...
1
vote
1answer
64 views

What are the virtual particles generated during the Hawking radiation?

What are the virtual particle pairs generated during the Hawking radiation? If a photon is emitted by Hawking radiation, what is its negative energy partner which fell into the black hole? Does it ...
1
vote
1answer
58 views

External source of virtual particles near a black hole?

I've just read the following quote from the Wikipedia page on Hawking Radiation... In order to preserve total energy, the particle that fell into the black hole must have had a negative energy ...
0
votes
1answer
69 views

Can photons travel faster than $c$? (Feynman Lectures)

I apologise for the very non-technical nature of this question. I am new to QED and perhaps am interpreting things in the wrong way, but I'll ask anyway, and hopefully someone can provide a ...
3
votes
0answers
91 views

Feynman Toy Model Constraints on Number of Each Kind of External Lines

(From my homework) In our toy model we have three kinds of spinless particles: $A$, $B$, and $C$. The primitive vertex of decay/interaction is shown below: My actual problem statement says: ...
3
votes
0answers
47 views

Scattering theory on Schrodinger and Feynman languages

Recently I heard that both of "languages" of scattering theory (formal solution by method of classical scattering theory and its reworking by Feynman with his rules) predict virtual particles. But for ...
3
votes
0answers
107 views

At what expansion rate (H) would virtual particles be ripped apart into real particles, and what might be the density (temperature) of such an event?

Is it even possible for a virtual particle-antiparticle pair to be torn apart by cosmological expansion? Virtual particle-antiparticle pairs are ripped apart near black hole event horizons, creating ...
2
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0answers
57 views

Can the rate of virtual pair production from vacuum be computed?

Consider for instance the QED Lagrangian. Is it possible to compute the rate of virtual electron-positron creation from the vacuum?
2
votes
0answers
165 views

photon and Z boson interference?

I'm not certain that this question will make sense, but here goes... In most monte carlo generators, when Z events are produced, there is a lower mass cutoff on the Z pole. I've been told that this ...
1
vote
0answers
31 views

How to parametrize off-shellness?

The energy of a massive on-shell particle of mass $m$ and three-momentum $\vec{p}$ satisfies $$E_\vec{p} = \sqrt{\vec{p}^2+m^2}. $$ What would be the analogous expression for an off-shell particle? ...
1
vote
0answers
69 views

Hawking radiation at the mouth of Schwarzschild wormholes

I was researching a question for another post and it occurred to me that you might expect to see Hawking radiation at the mouth of wormholes. Given the mechanism of Hawking radiation at the event ...
1
vote
0answers
77 views

EMF induced in a dynamo is by photons of permanent magnets?

i know little about the quantum field theory and also that the permanent magnets have there fields because of exchange of virtual photons across or around the ends. so when we take a dynamo and the ...
1
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0answers
83 views

How often can virtual particle/antiparticle pairs form real particles in a space expanding sufficiently fast to do this?

And if the rate of expansion of the universe becomes sufficient for virtual particles to be ripped apart into real particles, what effect would the mass of these particles have on the rate of ...
1
vote
0answers
253 views

Are virtual photons affected by effective gravity in non-linear quantum electrodynamics?

Quantum electrodynamics based upon Euler-Heisenberg or Born-Infeld Lagrangians predict photons to move according to an effective metric, which is dependent on the background electromagnetic field in a ...
0
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0answers
30 views

Experiment validating existence of virtual particle

I'm curious about virtual particle whether do they really exists, therefore I dug out an experimental theory called lamb shift by measuring the difference between the two energy levels of a hydrogen ...
0
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0answers
51 views

Rest masses, binding energy - mechanism for negative mass

Let us have an two objects (in a box) both of mass $m_0$ far from each other. They attract each other and at some moment their distance is close and they have substantial kinetic energy. Something ...
0
votes
0answers
49 views

Physical meaning of the coupling matrix in Fermi golden rule

I am calculating the energy transfer rate using Fermi golden rule where the coupling matrix $M$ is obtained using second order pertubation method. $$ \Gamma_{tran}=\frac{2\pi}{\hslash}|M|^{2}\rho$$ ...
0
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0answers
15 views

Does the mediation of electric or magnetic force require distinct electron orbitals?

In the case of ordinary photons of light, matter interacts with light via electrons that orbit the nucleus. If the specific energy of a photon E = hv can be found in the atom as the energy difference ...
0
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0answers
59 views

Polarizing virtual photons to make fusion easier?

So, this is probably incredibly foolish, outlandish, etc but I figure I'd post it anyways. Basically I was thinking about how the Deuterium nuclei repel each other and how they do this by exchanging ...
0
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0answers
124 views

In a theory of quantum gravity, does the gravitational coupling “constant” actually depend on the scale of the systems involved in the interaction?

In the following I will give some arguments that will indicate that the gravitational coupling "constant" actually depends on the scale (space and time) of the interacting systems. The question is: ...
0
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0answers
87 views

Born rule and Feynman propagators

Let us assume that we want to describe the full process of photon emission by electron A and absorption by electron B. Therefore electron B must be on the forward lightcone of electron A. In the ...
0
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0answers
76 views

Possible values of energies and impulses of virtual photon emitted by real electron

I need to find the possible values of energies and impulses of virtual photon emitted by real electron. I don't understand how to compute it (look to the text below). Let's introduce the free ...