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1vote
0answers
65views

The field strength is a primary field

I've often read (and used in computations) that the field strength tensor $F_{\mu\nu}$ is a primary field. What is a straightforward way to see this? Moreover, does this property imply any ...
Geigercounter's user avatar
1vote
1answer
104views

Does the Field strength transform under a conformal transformation?

I'm trying to prove that the Maxwell action $$S = -\frac{1}{4}\int d^d x \; F_{\mu\nu} F^{\mu\nu}$$ is conformally invariant only if $d=4$. For this I read this question that argues that the integrand ...
Geigercounter's user avatar
1vote
1answer
156views

Proving the Maxwell action is conformally invariant

I want to show that the Maxwell action $$S = -\frac{1}{4}\int d^4 x F_{\mu\nu} F^{\mu\nu}$$ is invariant under conformal transformations in $d=4$. For this I considered the proof given in Zee's book ...
Geigercounter's user avatar
0votes
1answer
200views

Electromagnetic tensor in a FRW metric

In some papers [like https://arxiv.org/pdf/2204.06883.pdf, eq. (31) ], I see that the Electromagnetic tensor field, for a FRW metric (written in a conformal way) \begin{equation} ds^{2} = a^{2}(\tau) \...
gravitone123's user avatar
0votes
1answer
737views

Electric field produced by a capacitor consisting of two parallel plates of different lengths: field lines and edge effect

It is known that the following integral equation describes the electrostatic field produced by a capacitor consisting of two parallel circular plates, derived in this paper (download for free) $$f(x)...
Enter's user avatar
0votes
1answer
66views

Dilatations and action on derivatives of fields

How do derivatives of fields transform under dilatations? Specifically I am interested on what I misunderstand with the example: Consider a theory that has a field $A_\mu$ that transforms under ...
Michael's user avatar
3votes
1answer
2kviews

What is the significance of the conformal invariance of electrodynamics in a covariant formulation?

I am a confused about the role of symmetry transformations in a covariant formulation. Maxwell's equations can be shown to be invariant under conformal transformations. See e.g. here: https://arxiv....
exchange's user avatar
11votes
0answers
663views

Special conformal transformations and image charges

Let us consider a grounded conducting sphere with radius $r$ and a point charge $e$ at a distance $R>r$ from the center of the sphere. For simplicity, we can choose the sphere centered at the ...
Brightsun's user avatar
2votes
0answers
308views

Conformal transformation: electric field of dipole

In beautiful paper (open access) authors calculate analytically optical response of "kissing" nanowires. Authors use method of "conformal transformation". Firstly, authors consider dipole (dipole ...
Nigel1's user avatar
11votes
1answer
1kviews

Conformal invariance of Electromagnetic field action

What is the significance of Conformal invariance of Electromagnetic field action? What does it lead to? And how can we break it?
Rahul's user avatar
  • 1,145
3votes
0answers
1kviews

Is classical electromagnetism conformally invariant? (and a bit of general covariance)

The contest is a flat $4d$ Minkowsky space. A conformal transformation is a diffeomorphism $\tilde x(x)$ such that the metric transforms as \begin{equation*} \tilde g_{\tilde \mu \tilde \nu} = w^2(x) ...
tbt's user avatar
  • 616
3votes
2answers
2kviews

Invariance of Maxwell's Equations under inverting variables - Reference and use

Some months ago, an ArXiv paper mentioned in passing that Maxwell's Equations were invariant under reciprocating the variables, or at least this results in a dual set of Maxwell Equations. (Actually I ...
John R Ramsden's user avatar

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