RT Journal Article T1 Partition functions and the continuum limit in Penner matrix models A1 Álvarez Galindo, Gabriel A1 Martínez Alonso, Luis A1 Medina, helena AB We present an implementation of the method of orthogonal polynomials which is particularly suitable to study the partition functions of Penner random matrix models, to obtain their explicit forms in the exactly solvable cases, and to determine the coefficients of their perturbative expansions in the continuum limit. The method relies on identities satisfied by the resolvent of the Jacobi matrix in the three-term recursion relation of the associated families of orthogonal polynomials. These identities lead to a convenient formulation of the string equations. As an application, we show that in the continuum limit the free energy of certain exactly solvable models like the linear and double Penner models can be written as a sum of Gaussian contributions plus linear terms. To illustrate the one-cut case we discuss the linear, double and cubic Penner models, and for the two- cut case we discuss theoretically and numerically the existence of a double-branch structure of the free energy for the Gaussian Penner model. PB IOP Publishing Ltd SN 1751-8113 YR 2014 FD 2014-08-08 LK https://hdl.handle.net/20.500.14352/34935 UL https://hdl.handle.net/20.500.14352/34935 LA eng NO ©IOP Publishing Ltd.The financial support of the Ministerio de Ciencia e Innovación under project IS2011-22566 is gratefully acknowledged NO Ministerio de Ciencia e Innovación (MICINN) DS Docta Complutense RD 29 jun 2025