Talk:Lagrangian (field theory)

Text and/or other creative content from Lagrangian was copied or moved into Lagrangian field theory with this edit. The former page's history now serves to provide attribution for that content in the latter page, and it must not be deleted as long as the latter page exists.

Should have been it's own article long ago

The analytical mechanics and especially classical field theory articles on WP are currently a mess. Anything similar (e.g. Lagrangians for systems of particles and Lagrangian densities for fields) are mushed into each other within the same articles. Things would be much easier to follow if there were separate articles on general analytical mechanics, general classical field theory, Lagrangian mechanics, Lagrangian field theory, Hamiltonian mechanics, and Hamiltonian field theory.

[1] The scope of Lagrangian is too big by including Lagrangian mechanics and Lagrangian field theory, and even seems redundant.

All the Lagrangian mechanics content (formalism, equations, examples, history, etc.) will be split off to Lagrangian mechanics, and all the field theory content (formalism, equations, examples, history, etc.) to another article Lagrangian field theory (which currently redirects to this page Lagrangian).

Then "Lagrangian" will be redirected to the Lagrangian (disambiguation) page with the latter including links to the new Lagrangian mechanics and Lagrangian field theory articles (which makes sense, since in the literature "Lagrangian density" is usually referred to as a "Lagrangian" anyway). Obviously, the relation between the two can be mentioned and both articles can link to each other.

By contrast, this is already the case for Hamiltonian mechanics, Hamiltonian field theory, and "Hamiltonian" is correctly a disambiguation page. M∧Ŝc²ħε И_τlk 09:53, 5 August 2015 (UTC)[reply]

Summary of main content transfers

So don't claim I stole anyone's work because the credit is given in these links! M∧Ŝc²ħε И_τlk 11:26, 5 August 2015 (UTC)[reply]

Article name

I think a more appropriate name is Lagrangian (field theory). Lagrangian field theory is probably much more general, see Lagrangian system and references therein for starters. (The GMS 2011 reference is downloadable from ResearchGate.) YohanN7 (talk) 13:41, 5 August 2015 (UTC)[reply]

OK, we can move the page later, but let's not move it too quickly since double redirects could appear. A lot of linking needs to be fixed as it is (but I'm glad you raised the point sooner than later, so I/anyone can redirect to Lagrangian (field theory) instead of Lagrangian field theory). M∧Ŝc²ħε И_τlk 14:32, 5 August 2015 (UTC)[reply]

Hmmmm. By the same token, we should have two articles, Lagrangian (mechanics) and Lagrangian mechanics. Possibly stuff that went into Lagrangian mechanics during split of Lagrangian could go into a new Lagrangian (mechanics). Lagrangian mechanics is becoming fat. But I don't think we should rush. Others may want to chip in (now when the see that things are acutually happening). YohanN7 (talk) 17:04, 5 August 2015 (UTC)[reply]

As currently written, it should be moved to Examples of Lagrangians, because it currently says approximately nothing at all about Lagrangians in general. It just defines a few terms, and then piles on the examples. None of the theory is covered, none of the theorems, nada zippo zilch. Yes, these examples are key examples needed for explaining the theory, but, the notation used for the examples dates back to e.g. Itzykson & Zuber-style notion, which is great for physics and for teaching collider-physics calculations, but is terrible for expressing theorems. It is kind-of weird, but Wikipedia seems to be metastasizing into a compendium of knowledge as it was 50 years ago, using the notation from 50 years ago, like an insect sealed in amber. But maybe this is what happens when obscure cutting-edge ideas morph into textbook-standard material which is then passed to increasingly younger students by increasingly older professors. A continuum across generations, I guess. 67.198.37.16 (talk) 19:35, 30 October 2020 (UTC)[reply]

Wrong Wikidata element?

I noticed that every other article associated to the same WD element refers to the Lagrangian function in general, while this article refers to Lagrangian field theory. Shouldn't it be necessary to create another WD element related to Lagrangian field theory? --Datolo12 (talk) 14:15, 26 February 2021 (UTC)[reply]

Mexican Hat??

ok why is it called the "mexican hat potential" and not just the sombrero potential? that feels a bit insensitive. i made the edit so it isn't just weird but if you're mad about it that's on me.Starcores (talk) 17:53, 30 November 2021 (UTC)[reply]

Please give a reason apart from WP:Idontlikeit. Xxanthippe (talk) 21:31, 30 November 2021 (UTC).[reply]

Sombrero is the generic Spanish term for hat; for instance a cowboy hat is a sombrero de vaquero, while a Mexican hat would probably be distinguished as a sombrero mexicano. So, it's actually your question, itself, that is from the (relatively insensitive) perspective of an outsider. The potential has that name, because it is shaped most closely like a Mexican hat, not a Stetson, not a beanie (sombrero de gorro). — Preceding unsigned comment added by 2603:6000:AA4D:C5B8:0:3361:EAF8:97B7 (talk) 18:51, 22 February 2022 (UTC)[reply]