Forrester–Frankel hard-edge gap-ratio asymptotic conjecture

Let Eβhard(n;(0,s);βa/2)E^{\rm hard}_{\beta}(n;(0,s);\beta a/2) denote the hard-edge probability of finding exactly nn eigenvalues in (0,s)(0,s) for the β\beta-ensemble, with parameter aa, and let τβa/2,βhard(n)\tau_{\beta a/2,\beta}^{\rm hard}(n) be the stated constant. For βnZ0\beta n\in\mathbb Z_{\ge 0}, define

τβa/2,βhard(n)=2(a+n)βnn!(β2)n(a+n1)β/2j=1βnΓ(a+2j/β)(2π)1/2j=0n1Γ(1+(j+1)β/2)j=n2n1Γ(1+(j+a)β/2).\tau_{\beta a/2,\beta}^{\rm hard}(n)={2^{-(a+n)\beta n}\over n!}\left({\beta\over2}\right)^{n(a+n-1)\beta/2}\prod_{j=1}^{\beta n}{\Gamma(a+2j/\beta)\over(2\pi)^{1/2}}\,{\prod_{j=0}^{n-1}\Gamma(1+(j+1)\beta/2)\over\prod_{j=n}^{2n-1}\Gamma(1+(j+a)\beta/2)}.

Hard-edge gap-ratio asymptotic conjecture. As ss\to\infty,

Eβhard(n;(0,s);βa/2)Eβhard(0;(0,s);βa/2)=τβa/2,βhard(n)exp(β{sn+(n22+na2)logs1/2})(1+O(1s1/2)).{E^{\rm hard}_{\beta}(n;(0,s);\beta a/2)\over E^{\rm hard}_{\beta}(0;(0,s);\beta a/2)}=\tau_{\beta a/2,\beta}^{\rm hard}(n)\exp\left(-\beta\left\{-\sqrt{s}\,n+\left({n^2\over2}+{na\over2}\right)\log s^{1/2}\right\}\right)\left(1+{\rm O}\left({1\over s^{1/2}}\right)\right).

This conjecture gives the large-ss asymptotics of the hard-edge spacing probabilities relative to the gap probability. The source presents the constant explicitly when βnZ0\beta n\in\mathbb Z_{\ge0}; its validity beyond that case is not resolved here.

Sources & referencesView supporting material

Primary source

Peter J. Forrester, “Asymptotics of spacing distributions at the hard edge for β-ensembles”, arXiv:1208.2388 (2012).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.