Conditional thinning and multiplicative statistics of Laguerre-type orthogonal polynomial ensembles
Leslie Molag, Guilherme L. F. Silva, Lun Zhang
TL;DR
This work analyzes the local statistics at the hard edge for Laguerre-type orthogonal polynomial ensembles under a position-dependent multiplicative deformation, interpreting it as conditional thinning. Using a novel Riemann-Hilbert framework with nonconstant jumps, the authors derive a universal limiting kernel, the conditional thinned Bessel kernel $\mathsf K_\alpha$, expressed via a function $\Phi$ solving a nonlocal integrable system that generalizes Painlevé-type structures. They establish a deformation representation for multiplicative statistics, showing convergence to $\mathsf L_\alpha^{(Bes)}$, and connect the nonlocal equations to a Markovian-type Lax pair; for $m=1$ the nonlocal equation reduces to a local PDE capturing the same integrable structure as recent Bessel-process work by Ruzza. The analysis combines a carefully constructed model RHP, a steepest-descent analysis, and global-to-local parametrices to yield precise kernel and statistic asymptotics, thereby extending hard-edge universality to conditional thinning and clarifying its integrable underpinnings with potential applications to related multiplicative-statistics settings.
Abstract
We study the local statistics of orthogonal polynomial ensembles near a hard edge, subject to a multiplicative deformation of the measure. Probabilistically, this deformation corresponds to a position-dependent conditional thinning of the particles. We prove that, under critical hard edge scaling and for a large class of potentials and deformation symbols, the correlation kernel of the conditional ensemble converges to a universal limit, which we identify as the conditional thinned Bessel point process. We derive an explicit expression for this limiting kernel in terms of the solution to a nonlocal integrable system depending on a parameter. For a special choice of the parameter, this system was recently identified in the study of multiplicative statistics of the Bessel point process. Our results establish that this system governs the full correlation structure of the conditional Bessel point process, extending the classical connection between the standard Bessel kernel and the Painlevé V equation.
