Local Bernstein theory, and lower bounds for Lebesgue constants

(terrytao.wordpress.com)

29 points | by jjgreen 3 days ago

2 comments

  • _alternator_ 44 minutes ago
    Fascinating discussion including showing how LLMs are helping push the state of the art:

    > I still did not see how to prove this inequality, but I decided to try my luck giving it to ChatGPT Pro, which recognized it as an {L^1} approximation problem and gave me a duality-based proof (based ultimately on the Fourier expansion of the square wave). With some further discussion, I was able to adapt this proof to functions of global exponential type (replacing the Fourier manipulations with contour shifting arguments, in the spirit of the Paley-Wiener theorem), which roughly speaking gave me half of what I needed to establish (2).

    > As a side note, this latter argument was provided to me by ChatGPT, as I was not previously aware of the Nevanlinna two-constant theorem.

    This mirrors my experience with these tools for math. Great for local problems and chatting through issues. Still can’t do the whole thing in one shot but getting there.

  • tensegrist 54 minutes ago
    Presumably one reason this is of interest here:

        The proof proceeds by a modification of the Duffin–Schaeffer argument, together with the two-constant theorem of Nevanlinna (and some standard estimates of harmonic measures on rectangles) to deal with the effect of the localization. (As a side note, this latter argument was provided to me by ChatGPT, as I was not previously aware of the Nevanlinna two-constant theorem.)
    • chromacity 38 minutes ago
      Which I find funny in a way: I'm sure that almost no one here understands the article, grasps the significance of this problem in mathematics, or can meaningfully comment on the difficulty of solving it. But we'll still have opinions because the article mentions a popular tool some of us like, some of us dislike, and some are ambivalent about.

      It would be surreal if a carpentry forum was regularly abuzz about mountaineering because climbers use a hammer-shaped tool.

      • adampunk 0 minutes ago
        It is deeply hilarious to watch software engineers become, at long last, bikeshedders.