All Questions
Tagged with quantum-electrodynamics photons
333
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Questions about QED Corrections to Coulomb's law and Electromagnetic Wave Equation
As a disclaimer, this is somewhat similar to this unanswered question, but not entirely.
In standard QED theory, it is frequently demonstrated that the derivation of the Coulomb Potential can be found ...
3
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1
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43
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Photon Mass Regulator in IR divergences
On Schwartz's QFT page 333, he metions that there is infrared divergence when we try to renormalized the two-point function of electron field in on-shell substraction scheme,
$$\frac{d}{d\,p_{\mu}\...
- 629
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33
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Link between photon helicity and polarization of $A^\mu$ electromagnetic potential
From Wigner theorem we know that the irreducible unitary representation of the Poincarè group for massless and spin 1 particle is labelled by the momentum $p_\mu$ and the two possible helicity $+1,-1$ ...
- 613
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2
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How is light interference explained with photons?
In the classical model of light as an EM wave, interference is a trivial consequence of the linearity of the wave equation. Now, if we model light as collections of photons, how is light interference ...
- 1,775
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Destructive interference pattern perpendicular to photon's propagation direction
I'm studying the interference pattern for light. For example, the following is the interference pattern for double slit experiment:
I'm curious to know if there is an existing interference pattern ...
- 81
4
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What happens if obstacles (walls) been put where destructive interference occurs in double slit experiment?
If photon doesn't have probability to be in dark (destructive interference) area, what will be the effect of adding obstacles (walls) in the dark (destructive interference) area for the double slit ...
- 81
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Spinor-helicity formalism: relationship between 1 and 2 reference vector setups
The spinor-helicity formalism is usually set up so that for a massless vector boson (photon or gluon) with momentum $k$ an arbitrary reference momentum $p$ is introduced and the corresponding ...
- 312
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Feynman trajectories of a photon from entangled pair
In a pair of Entangled photons does any of the two photons has the Feynman trajectories of the other one? Must the possible trajectories of photon 2 be taken in the Feynman's path integral for the ...
- 651
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How does a photon look like in QFT? [closed]
It is very well known that in QFT the particles are excitations of the field. But how exactly is a free photon looking like in spacetime? What is it shape in free space? And what is in fact in the ...
- 651
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425
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Is Feynman's Compton scattering diagram the same as the one in most books?
Feynman used the following Compton scattering diagram:
Whereas most books use this diagram in their derivation:
Is there a way to relate the two? Feynman's diagram makes more sense to me ...
- 187
3
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124
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Are EM waves telling us the probability of finding a photon?
I feel like I've been frequently presented with an interpretation of EM waves that goes something like this:
Light is an oscillating electromagnetic field. Because changes in the electric field ...
- 203
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Why do I find different polarization vector completeness relations?
I am currently working on computing the cross section of Compton scattering in QED and in the process need to evaluate an expression of the following form:
$$ \sum_{\lambda}^{} \epsilon^{\mu} (\...
- 101
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Pushing solid objects by photon exchange
As I understood it,
the reason I cannot stick my hand through a metal block is due to the repelling force between electrons in my hand and in the block. QED depicts two electrons repelling with a ...
- 49
4
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2
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105
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How to distinguish Coulomb and radiative parts of the electromagnetic field?
In classical electromagnetism, the EM field can be described by a 4-potential $A^\mu$. This potential describes two different phenomena.
Static fields: A static charge $q$ at fixed position $r_0$ ...
- 4,827
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Can there be an electron without photons?
Can the electron field be excited while the photon field is not? I'm guessing the answer is no, because electrons are supposed to interact with their own electric field. I don't know about ...
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