Talk:Lagrangian mechanics

Curly L?
Would it not be more standard / look better to uses a curly $$\mathcal{L}$$ for the Lagrangian rather than a regular capital L?

Blitzer99 (talk) 22:21, 2 December 2020 (UTC)


 * I agree. This is a convention I've usually seen followed, especially because in a lot of places people use L for angular momentum as well, which may lead to confusion. It ought to be changed. EffyJohn (talk) 15:43, 30 September 2021 (UTC)

Possible error in the introduction using the terms ″variation″
In the introduction of this page the term $$ \delta \mathcal{S}:[t_0,t_1] \rightarrow \mathbb{R} $$ is defined and called the ″variation″, which is possibly erroneous (although $$ \delta \mathcal{S}$$ is indeed a Gateaux derivative). Comparing $$ \delta \mathcal{S} $$ with the definition of ″variation″ (of $$x_0$$) in the Wikipedia page virtual displacement, one finds instead that a variation is a function as well of the parameter ε. In other words, the "variation" is not equal to the "Gateaux derivative". However, it might be that the term "variation" is defined in some other way (which is then inconsistent with the definition in virtual displacement). Doubledipp (talk) 16:45, 16 April 2022 (UTC)Doubledipp


 * There is some discrepancy between math and physics in how the term "variation" is used. In math, $$\delta {\cal S}$$ could have been (and is in some sources) called infinitesimal variation. StrokeOfMidnight (talk) 06:46, 20 April 2022 (UTC)

Lead section rewritten
I've rewritten the lead section per MOS:INTRO to get rid of the equations and the more complicated mathematical language. All of that stuff appears later in the article, and the lead needs to provide a less technical overview of the topic.PianoDan (talk) 20:05, 25 April 2022 (UTC)

Suggestion about
"Any variation of the functional gives an increase in the functional integral of the action."

Delete this sentence and discuss saddle point in the sentence before it. 210.61.187.232 (talk) 11:07, 17 June 2024 (UTC)


 * I deleted the sentence. Johnjbarton (talk) 15:01, 17 June 2024 (UTC)