Orthogonal polynomials, asymptotics, and Heun equations

Y Chen, G Filipuk, L Zhan - Journal of Mathematical Physics, 2019 - pubs.aip.org
The Painlevé equations arise from the study of Hankel determinants generated by moment
matrices, whose weights are expressed as the product of “classical” weights multiplied by …

Asymptotics for a singularly perturbed GUE, Painlevé III, double-confluent Heun equations, and small eigenvalues

J Yu, C Li, M Zhu, Y Chen - Journal of Mathematical Physics, 2022 - pubs.aip.org
We discuss the recurrence coefficients of the three-term recurrence relation for the
orthogonal polynomials with a singularly perturbed Gaussian weight w (z)=| z| α⁡ exp− z 2 …

Painlevé V and confluent Heun equations associated with a perturbed Gaussian unitary ensemble

J Yu, S Chen, C Li, M Zhu, Y Chen - Journal of Mathematical Physics, 2023 - pubs.aip.org
We discuss the monic polynomials of degree n orthogonal with respect to the perturbed
Gaussian weight w (z, t)=| z| α (z 2+ t) λ e− z 2, z∈ R, t> 0, α>− 1, λ> 0⁠, which arises from a …

On semiclassical orthogonal polynomials associated with a Freud‐type weixght

D Wang, M Zhu, Y Chen - Mathematical Methods in the Applied …, 2020 - Wiley Online Library
The recursion relationship: z P n (z)= P n+ 1 (z)+ β n P n− 1 (z), n= 0, 1, 2… is satisfied by all
monic orthogonal polynomials in regard to an arbitrary Freud‐type weight function. In current …

Discrete, Continuous and Asymptotic for a Modified Singularly Gaussian Unitary Ensemble and the Smallest Eigenvalue of Its Large Hankel Matrices

D Wang, M Zhu - Mathematical Physics, Analysis and Geometry, 2024 - Springer
This paper focuses on the characteristics of the Hankel determinant generated by a modified
singularly Gaussian weight. The weight function is defined as: w (z; t)=| z| α e-1 z 2-tz 2-1 z 2 …

Painlevé IV, σ-form, and the deformed Hermite unitary ensembles

M Zhu, D Wang, Y Chen - Journal of Mathematical Physics, 2021 - pubs.aip.org
We study the Hankel determinant generated by a deformed Hermite weight with one jump w
(z, t, γ)= e− z 2+ tz| z− t| γ (A+ B θ (z− t))⁠, where A≥ 0, A+ B≥ 0, t∈ R, γ>− 1, and z∈ R. By …

On semi-classical orthogonal polynomials associated with a modified sextic Freud-type weight

AS Kelil, AR Appadu - Mathematics, 2020 - mdpi.com
Polynomials that are orthogonal with respect to a perturbation of the Freud weight function
by some parameter, known to be modified Freudian orthogonal polynomials, are …

Semi-classical Orthogonal Polynomials Associated with a Modified Gaussian Weight

Y Ding, C Min - Results in Mathematics, 2024 - Springer
We are concerned with the monic orthogonal polynomials with respect to the modified
Gaussian weight w (x)= w (x; s):= eN [x 2+ s (x 6-x 2)], x∈ R with parameters N> 0 and s∈[0 …

Laguerre–Hahn orthogonal polynomials on the real line

MDN Rebocho - Random Matrices: Theory and Applications, 2020 - World Scientific
A survey is given on sequences of orthogonal polynomials related to Stieltjes functions
satisfying a Riccati type differential equation with polynomial coefficients—the so-called …

Orthogonal polynomials, bi-confluent Heun equations and semi-classical weights

D Wang, M Zhu, Y Chen - Journal of Difference Equations and …, 2020 - Taylor & Francis
In this paper, we focus on four weights ω (z, s)= z λ e− N (z+ s (z 2− z)), where z∈(0,∞), λ>−
1, 0≤ s≤ 1, N> 0; ω (z, t)= z λ e− z 2+ tz, where z∈(0,∞), λ>− 1, t∈ R; ω (z, t 1)= e− z 2 A+ B …