All Questions
Tagged with electromagnetism mathematical-physics
15
questions with no upvoted or accepted answers
28
votes
1
answer
1k
views
Electric charges on compact four-manifolds
Textbook wisdom in electromagnetism tells you that there is no total electric charge on a compact manifold. For example, consider space-time of the form $\mathbb{R} \times M_3$ where the first factor ...
- 401
7
votes
0
answers
443
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1-form formulation of quantized electromagnetism
In a perpetual round of reformulations, I've put quantized electromagnetism into a 1-form notation. I'm looking for references that do anything similar, both to avoid reinventing the wheel and perhaps ...
- 9,948
4
votes
1
answer
577
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Can one force the octupole moments of a charge distribution (neutral and with vanishing dipole moment) to vanish using a suitable translation?
In a previous question, I noted that if you have a charge distribution with nonzero charge, then it is possible to choose an origin (at the centre of charge) which makes its dipole moment vanish, and ...
- 134k
3
votes
0
answers
966
views
Mathematics of Surface Divergence and Surface Curl
While studying electrodynamics I found two functions - Surface Divergence and Surface Curl - that seem to condense the formulas for superficial discontinuities of the electric and magnetic fields ...
- 88
2
votes
0
answers
101
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Free electromagnetic field BV action
I am trying to write down the extended BV-action of the free electromagnetic field in a physicist notation, but I don't find it anywhere. I found the following formula in example 3.1. of the paper ...
- 689
2
votes
0
answers
305
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Doubts about the Aharonov-Bohm effect
In F. Schwabl, Quantum Mechanics p.148 it is explained that if we have a particle in an electromagnetic field given by potentials $\varphi$ and $\mathbf{A}$ with wave function $\psi$, then a gauge ...
1
vote
0
answers
47
views
Why shouldn't I choose my boundary limits corresponding to the direction I'm integrating?
I have a question regarding the choice of boundary limits when it comes to vector integrals. Why shouldn't I always choose the boundary limits corresponding to the direction I'm integrating. I.e why ...
- 43
1
vote
0
answers
331
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Wave Equations from Decoupling Maxwell's Equations in Bianisotropic Media
For several days now, I have been trying to decouple Maxwell's equations in bianisotropic media so that I end up with a form that involves only one variable (of E, D, B, H), i.e. a so-called 'wave ...
- 591
1
vote
0
answers
148
views
Boundary conditions for 2D helical waveguide
I'm interested in looking at standing wave solutions for the wave equation on a 2D annulus, with the twist that the annulus is "streched" in to a helix in 3D, but so that the rings themselves are 2-...
- 300
0
votes
0
answers
16
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Effects of Localized Medium Changes on Field Propagation
I've studied various theories related to fields. These theories often include equations describing how the activity of a source is transmitted to other locations. The properties of the medium ...
- 695
0
votes
0
answers
25
views
Charge Density Of A Conducting Strip
I am currently doing a project which requires me to figure out the charge density of a strip. Assume that the strip is isolated in a vacuum.
Assume the strip is 1 dimensional, kind of like a rod. What ...
0
votes
0
answers
286
views
General proof of independence of TM and TE modes in a waveguide
In electromagnetic field analysis for a typical waveguide that has a uniform cross section along its axial direction (say $z$), we often describe the E and H fields conveniently in terms of their ...
- 632
0
votes
1
answer
56
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For closed circuits, why can't we have more than one $f(r)$?
Force between current elements depends on a function of angles [$f(\eta, \theta, \theta^{\prime})$] and also on a function of distance between them [$f(r)$] .
For closed circuits, there are more ...
- 772
0
votes
0
answers
203
views
Regarding Ampere's Circuital Law
If I am to show that Ampere's Circuital law holds true for any arbitrary closed loop in a plane normal to the straight wire, with its validity already established for the closed loop being a circle of ...
0
votes
1
answer
108
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Charge and current density fields
The charge and current density fields in classical electromagnetism are scalar real number fields on space time manifold. But these fields diverge/become infinite in case of point charges, how is this ...
- 1,578