English

Orthogonal polynomials in the spherical ensemble with two insertions

Classical Analysis and ODEs 2025-05-21 v2 Mathematical Physics math.MP

Abstract

We consider asymptotics of planar orthogonal polynomials Pn,NP_{n,N} (where degPn,N=n\mathrm{deg}P_{n,N}=n) with respect to the weight zw2NQ1(1+z2)N(1+Q0+Q1)+1,(Q0,Q1>0)\frac{|z-w|^{2NQ_1}}{(1+|z|^2)^{N(1+Q_0+Q_1)+1}}, \quad(Q_0,Q_1 > 0) in the whole complex plane. With n,Nn, N\rightarrow\infty and NnN-n fixed, we obtain the strong asymptotics of the polynomials, asymptotics for the weighted L2L^2 norm and the limiting zero counting measure. These results apply to the pre-critical phase of the underlying two-dimensional Coulomb gas system, when the support of the equilibrium measure is simply connected. Our method relies on specifying the mother body of the two-dimensional potential problem. It relies too on the fact that the planar orthogonality can be rewritten as a non-Hermitian contour orthogonality. This allows us to perform the Deift-Zhou steepest descent analysis of the associated 2×22\times 2 Riemann-Hilbert problem.

Keywords

Cite

@article{arxiv.2503.15732,
  title  = {Orthogonal polynomials in the spherical ensemble with two insertions},
  author = {Sung-Soo Byun and Peter J. Forrester and Arno B. J. Kuijlaars and Sampad Lahiry},
  journal= {arXiv preprint arXiv:2503.15732},
  year   = {2025}
}

Comments

41 pages, 9 figures

R2 v1 2026-06-28T22:27:37.285Z