Integrable Contour Kernels in Discrete $β=1,4$ Ensembles, Universality and Kuznetsov Multipliers
Miguel Tierz
TL;DR
The paper develops explicit double–contour (IIKS) representations for discrete β=1 and β=4 kernels associated with Meixner, Charlier, and Krawtchouk weights, unifying the orthogonal and symplectic cases through a single Cauchy–difference–quotient composition identity. This framework yields uniform proofs of bulk sine and edge Airy/Bessel universality, a Meixner→Laguerre hard–edge crossover, and an explicit A^{-1} correction arising from linearizing the difference–quotient at saddles. It further shows that archimedean Kuznetsov tests can be inserted as bounded contour multipliers without changing leading limits, while producing finite–size terms via the same linearization mechanism. The results connect integrable kernel theory with discrete random partitions and representation–theoretic models, offering practical tools for finite–N computations and potential crossovers to arithmetic deformations and number‑theoretic kernels. Overall, the work provides a versatile, uniform approach to universality and finite‑size corrections in discrete random matrix ensembles with broad implications for related combinatorial and number-theoretic structures.
Abstract
We obtain explicit double-contour representations for the correlation kernels of the discrete orthogonal ($β=1$) and symplectic ($β=4$) random matrix ensembles with Meixner, Charlier, and Krawtchouk weights. A single Cauchy--difference--quotient composition identity expresses all $β=1,4$ blocks in terms of the projection kernel and bounded rational multipliers. From these formulas we give short steepest-descent proofs of bulk and edge universality (sine/Airy/Bessel) with uniform error control, an explicit Meixner$\to$Laguerre hard-edge crossover, and a first $A^{-1}$ correction that follows directly from the integrable structure. Finally, we show that Archimedean Kuznetsov tests splice into the Pfaffian kernels by a bounded holomorphic symbol acting in the contour variable; the symbol enters only through the same Cauchy difference--quotient, so the leading sine/Airy/Bessel limits persist and the $A^{-1}$ term again comes from linearizing at the saddle(s).
