Template talk:Editnotices/Page/Mathematical descriptions of the electromagnetic field

Physics Template‑class

	Physics portal This template is within the scope of WikiProject Physics, a collaborative effort to improve the coverage of Physics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.PhysicsWikipedia:WikiProject PhysicsTemplate:WikiProject Physicsphysics articles
Template	This template does not require a rating on Wikipedia's content assessment scale.

This edit request has been answered. Set the |answered= or |ans= parameter to no to reactivate your request.

This template refers to part of the differential geometry formulation used for electromagnetism. At one point the Maxwell's equations article included this formulation, after a rewrite [1][2] this content (which the edit notice is referring to) was moved to Maths of EM field.

This edit notice should be moved to Template:Editnotices/Page/Mathematical descriptions of the electromagnetic field where it applies, it is irrelevant in Maxwell's equations now. z = z² + c 09:45, 17 July 2012 (UTC)[reply]

Done But the edit notice needs to be greatly cleaned up. Use {{editnotice}}, clarify what "the formula below" is referring to or otherwise reword it to make sense, put the formulas in <math>, and so on so it's easier to read. Anomie ⚔ 16:44, 18 July 2012 (UTC)[reply]

By my own judgement this would be the reworded notice:

4-current as 1-form and 3-form

Please note: the four-current J is defined as a 3-form here. ~~Please do not change d*F = *J to *d*F = J (LHS 1 form, RHS 3 form).~~ Please leave Maxwell's equations as

d\,{\star F}=J,dF=0

. In much of the literature J is defined as a 1-form (hodge star of our J) but the three-form version is much nicer (e.g., J is closed rather than co-closed) and much closer to physical intuition (e.g., for a spacelike 3-dimensional region V,

\int _{V}J=

total charge in V).

but I'm not proficient in differential geometry (yet) so I asked here just to make sure it makes sense. I asked the original creator (user:Koavf) but he was not sure either. Please wait before transplanting this with the current version. Thank you for moving it. z = z² + c 19:39, 18 July 2012 (UTC)[reply]

If

J

is a 3-form, then the correct formula is

J=d(\star F)

, but neither of the above. It is only

d(\star F)

which is a (not necessarily zero) 3-form, because

dF=0

, and Hodge duals to 3-forms are 1-forms in 4-space. Incnis Mrsi (talk) 07:50, 19 July 2012 (UTC)[reply]

d\star F=J

is the one in the article, the notice was supposed to indicate not changing some other formula to

\star d\star F=J

.

Lets just simplify it by writing

"leave Maxwell's equations as

d\star F=J,dF=0

"

in place of

"Please do not change

d\,{\star F}={\star J}

to

{\star d}\,{\star F}=J

(LHS 1 form, RHS 3 form)."

Agreed?z = z² + c 08:15, 19 July 2012 (UTC)[reply]

I tried fixing some of the article maths of EM field which includes both conventions (current as a 3-form and a 1-form), so ~~I'm not sure if this notice is even needed anymore...~~ this template notice may as well be deleted since the article now explains what the notice says anyway... z = z² + c 08:43, 19 July 2012 (UTC)[reply]

Do not say "d\star F", because LaTeX and MathJax think \star is a binary operator and resulting spacing is confusing. You can say "d\,{\star F}":

d\,{\star F}

if you dislike parentheses. Incnis Mrsi (talk) 09:07, 19 July 2012 (UTC)[reply]

Sorry I'll fix that. z = z² + c 09:28, 19 July 2012 (UTC)[reply]