Talk:Bernstein's Theorem on Unique Extremal

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Using Picard's theorem

In the book by Gelfand and Fomin it is noted that the problem of existence and uniqueness for a variational problem is more than existence and uniqueness for a differential equation, since the solution has to be defined over a region instead of in the neighbourhood. Quick look at the 1978 article revealed Picard's theorem not being mentioned, while the original is currently down. Julius (talk) 12:04, 16 January 2017 (EST)

The original mentions it on page 442, however my french is not that good. Anyway, it does not seem that using it would easily solve the problem, otherwise it would have been done already. Julius (talk) 15:07, 16 January 2017 (EST)

Title

Wikipedia shows at least 8 theorems when asked for Bernstein theorem, but none of them are related to calculus of variations in an obvious way. Until more of theorems related to this fields are found, I suggest naming it as "Bernstein's theorem on unique extremal" (or for, or something similar). This way the connection to the math. field in question is evident, without revealing too many details, while chance of confusion is reduced to minimum, since a simple google search provides close to no results regarding this theorem. For some reason, though, proofwiki does not pop out when looking for it. Julius (talk) 15:29, 16 January 2017 (EST)

As good a name as any. --prime mover (talk) 16:11, 16 January 2017 (EST)

Sources

I fixed the sources once more. Please look more closely at the text of the title and you will note the places where it had been corrected. Also note there is a reason behind the sources being ordered the way they were. Usually best, when amending a page, to take the latest version, it probably incorporates corrections on a previous version. --prime mover (talk) 14:13, 16 January 2017 (EST)