{ "id": "2402.11233", "version": "v1", "published": "2024-02-17T09:38:16.000Z", "updated": "2024-02-17T09:38:16.000Z", "title": "Asymptotics of the determinant of the modified Bessel functions and the second Painlevé equation", "authors": [ "Yu Chen", "Shuai-Xia Xu", "Yu-Qiu Zhao" ], "comment": "41 pages, 14 figures", "doi": "10.1142/S2010326324500035", "categories": [ "math-ph", "math.MP", "nlin.SI" ], "abstract": "In the paper, we consider the extended Gross-Witten-Wadia unitary matrix model by introducing a logarithmic term in the potential. The partition function of the model can be expressed equivalently in terms of the Toeplitz determinant with the $(i,j)$-entry being the modified Bessel functions of order $i-j-\\nu$, $\\nu\\in\\mathbb{C}$. When the degree $n$ is finite, we show that the Toeplitz determinant is described by the isomonodromy $\\tau$-function of the Painlev\\'{e} III equation. As a double scaling limit, %In the double scaling limit as the degree $n\\to\\infty$, we establish an asymptotic approximation of the logarithmic derivative of the Toeplitz determinant, expressed in terms of the Hastings-McLeod solution of the inhomogeneous Painlev\\'{e} II equation with parameter $\\nu+\\frac{1}{2}$. The asymptotics of the leading coefficient and recurrence coefficient of the associated orthogonal polynomials are also derived. We obtain the results by applying the Deift-Zhou nonlinear steepest descent method to the Riemann-Hilbert problem for orthogonal polynomials on the Hankel loop. The main concern here is the construction of a local parametrix at the critical point $z=-1$, where the $\\psi$-function of the Jimbo-Miwa Lax pair for the inhomogeneous Painlev\\'{e} II equation is involved.", "revisions": [ { "version": "v1", "updated": "2024-02-17T09:38:16.000Z" } ], "analyses": { "subjects": [ "33E17", "34M55", "41A60" ], "keywords": [ "modified bessel functions", "asymptotic", "toeplitz determinant", "deift-zhou nonlinear steepest descent method", "orthogonal polynomials" ], "tags": [ "journal article" ], "publication": { "publisher": "World Scientific" }, "note": { "typesetting": "TeX", "pages": 41, "language": "en", "license": "arXiv", "status": "editable" } } }