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    • CommentRowNumber101.
    • CommentAuthorDavid_Corfield
    • CommentTimeMay 25th 2021

    Are we entering the world of skew tableaux?

    • CommentRowNumber102.
    • CommentAuthorUrs
    • CommentTimeMay 25th 2021
    • (edited May 25th 2021)

    Aha, that’s a plausible possibility!

    Checking this is essentially straightforward, though it requires some work: Using our discussion at Cayley state on the group algebra we have its “density matrix” realization and “just” need to work out a tractable expression for the partial trace of that over the span of a Sym-subgroup inclusion.

    Maybe next week…

    • CommentRowNumber103.
    • CommentAuthorUrs
    • CommentTimeMay 28th 2021

    Finally finding time to look into some of these counting formulas for the number |sYTn(N)| standard Young tableaux with n boxes and at most N rows. So coming back to around #87:

    Looking now at the literature, I see that an asymptotic formula for |sYTn(N)| is the main result of Regev 81, whose theorem 2.10 says that:

    |sYTn(N)|n(2π)(N1)/2NN2/2γNn(N1)(N+2)/4Nnn(N1)/2x1xNi<j(xixj)D(x1,,xN)eN|x|2/2dx1dxN=(2π)12(N1)N12N2+nn14(N2+N)x1xNi<j(xixj)eN|x|2/2dx1dxN.

    Here under the braces in the first row I am indicating Regev’s notation which I have expanded out (using the definitions given on the bottom of his p. 3), and in the second line I have collected exponents.

    This would mean that the leading contributions in N to the max-entropy of the Cayley state in the limit of large n should be

    S0(pCayley)n12N2ln(N)14N2ln(n)+𝒪(N)
    • CommentRowNumber104.
    • CommentAuthorUrs
    • CommentTimeMay 28th 2021

    Ah, the last conclusion is not quite correct, as there is N-dependence also in the integration domain of the last factor. Since |x|2=Ni=1x2i𝒪(N), this last terms probably gives one more contribution at order N2 and independent of n.

    • CommentRowNumber105.
    • CommentAuthorUrs
    • CommentTimeMay 28th 2021
    • (edited May 29th 2021)

    We may compute the order of the integral term in #103 by decomposing it into an integral over a sector of a unit sphere (which gives a constant) times a Gaussian moment:

    0RN(N1)/2eNR2/2dR(N1/2)N(N1)/2=NN(N1)/4

    Hope I have the factors right.

    Therefore, it looks like we get a max-entropy at large n of the form

    S0(pCayley)na0+a2(n)N+a4(n)N2+a4(n)N2ln(N),

    Curiously, this would be the form of the entropy of Yang-Mills theory with N colors (e.g. (1.1) on p. 3 in arXiv:2105.02101) – the point being that besides plain powers of N, the leading contribution N2ln(N) is, in both cases, the second power of N times the logarithm of N.

    • CommentRowNumber106.
    • CommentAuthorUrs
    • CommentTimeMay 29th 2021
    • (edited May 29th 2021)

    I’ll stop doing incremental computations here in the comments, and instead put the computation into the entry (here).

    Following through along the above lines, I now get

    |sYTn(N)|nconst(2π)12(N1)N14(N2+N)+12nn14(N2N)
    • CommentRowNumber107.
    • CommentAuthorDavid_Corfield
    • CommentTimeMay 29th 2021
    • (edited May 29th 2021)

    Adding one more to the list

    a(n) ~ 3 * 5^(n+5)/(8 * Pi *n^5) A049401

    a(n) ~ 3/4 * 6^(n+15/2)/(Pi^(3/2)*n^(15/2)) A007579

    a(n) ~ 45/32 * 7^(n+21/2)/(Pi^(3/2)*n^(21/2)) A007578

    a(n) ~ 135/16 * 8^(n+14)/(Pi^2*n^14) A007580

    So you’d imagine it was

    a(n) ~ constN(n+NN14)/(πc(N)nNN14)

    So log(a(n))~nlogN+NN14logNNN14logn.

    Hmm, not quite tallying with yours.

    • CommentRowNumber108.
    • CommentAuthorDavid_Corfield
    • CommentTimeMay 29th 2021

    That 12n in your exponent of N should just be n. Fixed that on the page.

    Getting closer.

    So why do you have 14(N2+N) where I have 14(N2N)?

    Is it that my ’const’ is N-dependent?

    And my powers of π are going up by 1/2 every other step. So that will because there’s a gamma function contributing a (π) for odd arguments.

    • CommentRowNumber109.
    • CommentAuthorDavid_Corfield
    • CommentTimeMay 30th 2021
    • (edited May 30th 2021)

    Those estimates in #107 are due to Václav Kotěšovec who conjectures:

    aN(n)NnπN/2(Nn)N(N1)4Nj=1Γ(j2).
    • CommentRowNumber110.
    • CommentAuthorDavid_Corfield
    • CommentTimeMay 30th 2021
    • (edited May 30th 2021)

    But F.4.5.1 of the paper by Regev you mention in #105 concerns this value and looks slightly different. He also has a product of gamma function values at half-integers.

    aN(n)NnπN/2(Nn)N(N1)4Nj=1Γ(1+j2)2N1N!.

    Might be the same. (The shift in those two gamma terms would make for an extra N!2N.)

    In any case we’d need to know how the product of gamma functions varies with N. Perhaps the hint to use the Barnes G function helps. I got to some multiple of N2lnN with it.

    • CommentRowNumber111.
    • CommentAuthorDavid_Corfield
    • CommentTimeJun 1st 2021
    • (edited Jun 1st 2021)

    Continuing #109, Kotěšovec writes that

    Nj=1Γ(j2)=G(N/2+1)G(N/2+1/2)G(1/2),

    where G is the Barnes G-function.

    (14) there suggests that the greatest term in logG(1+z) is 12z2logz.

    • CommentRowNumber112.
    • CommentAuthorUrs
    • CommentTimeJun 1st 2021

    Thanks for the replies! And for spotting F.4.5.1 in Regev, I hadn’t seen that.

    So I must have been making a mistake in extracting the powers of N (=l) from Regev’s F.2.10. But I don’t see my mistake yet – this here was my reasoning:

    There are N(N1)/2 factors in D=i<j(). With each factor proportional to R, these give a global factor of RN(N1)/2 in the integrand of a Gaussian integral over R0 with standard deviation σ=N1/2, which hence yields “half” a Gaussian moment (N1/2)N(N1)/2=N14(N2N). Multiplied with the N12N2 hidden in Regev’s “γ”, this yields N14(N2+N). Or so it seems. (?)

    • CommentRowNumber113.
    • CommentAuthorDavid_Corfield
    • CommentTimeJun 1st 2021

    Well aren’t I seeing (#111) an extra 12(N/2)2log(N/2)+12((N1)/2)2log((N1)/2)14N2logN?

    We would need it to be twice this.

    • CommentRowNumber114.
    • CommentAuthorUrs
    • CommentTimeJun 1st 2021

    Oh, I see, right. (On the other hand, what “we need” would be a term 12Nln(N), not 12N2ln(N), no?)

    But maybe better to go with Regev’s theorem than with Kotěšovec’s conjecture: To Regev’s product of Gamma functions the Legendre relation applies, which should be helpful.

    • CommentRowNumber115.
    • CommentAuthorDavid_Corfield
    • CommentTimeJun 1st 2021
    • (edited Jun 1st 2021)

    I was going on your

    Multiplied with the N12N2 hidden in Regev’s “γ“…

    so adding on 12N2ln(N).

    But maybe better to go with Regev’s theorem than with Kotěšovec’s conjecture

    Regev’s F 4.5.1 is equal to Kotěšovec’s conjecture, right? The former’s product is shifted so we lose a Γ(1/2) and Γ(1) and gain Γ(1+N/2) and Γ(1+(N1)/2). The first two make π. The latter two are this multiplied by a product of half-integers to N/2 which is N!/2N.

    • CommentRowNumber116.
    • CommentAuthorDavid_Corfield
    • CommentTimeJun 1st 2021

    The latter fact is just an instance of the Legendre relation you just mentioned, for z=(N+1)/2.

    This product of Γ functions at half-integers is a product of these products taken at odd and then even half-integers. That’s why Kotěšovec has them in terms of the Barnes G-function which is just an extended form of double factorial.

    • CommentRowNumber117.
    • CommentAuthorUrs
    • CommentTimeJun 1st 2021

    I just meant that this “hidden” factor made the N2ln(N)-term come out as expected, but left the Nln(N)-term with the wrong sign. Anyways, as you observed, all this is besides the point, as there are more Nkln(N)-term hidden in the “combinatorial prefactors”, which I hadn’t appreciated.

    Regev’s F 4.5.1 is equal to Kotěšovec’s conjecture, right?

    Oh, okay, I hadn’t seen this yet.

    Maybe in Regev’s form the Gauss multiplication formula lends itself more naturally than Barne’s G-function to get all the terms, but I haven’t worked it out yet. Need to go offline now for a bit.

    • CommentRowNumber118.
    • CommentAuthorDavid_Corfield
    • CommentTimeAug 11th 2022

    Vague idea: I was wondering whether the ’Lorentzian’ qualifier in Lorentzian polynomial should point us to something physics-related, when I recalled this thread from last year.

    Since we were looking at probability distributions over Young tableaux, it’s interesting to see that Lorentzian polynomials (which are used to establish log-concavity of sequences, a2kak+1ak1, and so unimodality of sequences, as explained here) are cropping up in this area, as in

    • June Huh, Jacob P. Matherne, Karola Mészáros, Avery St. Dizier, Logarithmic concavity of Schur and related polynomials (arXiv:1906.09633)

    They’re touching on some physics directly in