Photon Interaction: Possible or Not?

[Dickfore]

In QED they can. The lowest order Feynman diagram corresponding to this interaction is:

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Since these diagrams have the 4 vertices, the transition amplitude corresponding to these diagrams is of the order $O(\alpha^{2})$, where $\alpha \equiv k e^{2}/\hbar c \approx \frac{1}{137}$ is the fine structure constant.

 

[Antiphon]

1) there is no wave function for a photon (and no Schrödinger equation)

I thought Maxwell's equations describe the evolution of the wavefunction of a photon.

 

[Count Iblis]

There is also the http://en.wikipedia.org/wiki/Primakoff_effect" , which has interesting consequences if axions exist. You then have an effective photon-photon-axion vertex. In the presence of a strong magnetic field, a photon can then oscillate into an axion and vice versa.

This can be used to send http://arxiv.org/abs/0704.0490" .

 

[threadmark]

Do photons emit from electrons instantly. It would suggest that photons move at different vectors relative to the electrons position in the atoms configuration. These photons travel at constant velocities so the possibility of two photons interacting traveling at the same vector;

• Given there is no obstacles to diffract or refract the photons course and;
• Given its vector isn’t distorted by gravity.
Cannot interact.

But this does not say that photons do not interact.
In its state/function i would think it wouldn’t inherit changes but that’s not to say they can’t occupy the same point in space. From a receprical point they do interact being they can have opposite Bearings. That is of course if electrons don’t emit photons instantly. TM

 

[tom.stoer]

I would suggest to stop the speculations and refer to QED.

Dickfore presented the lowest order Feynman diagrams that contribute to photon-photon scattering.

@Antiphon: Maxwell's equation are purely classical; in QED both the photon and the electron field are quantized; this results in quantum corrections like the diagrams Dickfore is referring to. According to Maxwell's equations photons do not interact directly, only via matter couplings. This carries over to QED: no direct interaction, only via Fermion loops.