RT journal article T1 Exceptional Legendre Polynomials and Confluent Darboux Transformations A1 García-Ferrero, María Ángeles A1 Gómez-Ullate Oteiza, David A1 Milson, Robert A2 Ingeniería Informática K1 exceptional orthogonal polynomials K1 Darboux transformations K1 isospectral deformations AB Exceptional orthogonal polynomials are families of orthogonal polynomials that arise as solutions of Sturm-Liouville eigenvalue problems. They generalize the classical families of Hermite, Laguerre, and Jacobi polynomials by allowing for polynomial sequences that miss a finite number of "exceptional" degrees. In this paper we introduce a new construction of multi-parameter exceptional Legendre polynomials by considering the isospectral deformation of the classical Legendre operator. Using confluent Darboux transformations and a technique from inverse scattering theory, we obtain a fully explicit description of the operators and polynomials in question. The main novelty of the paper is the novel construction that allows for exceptional polynomial families with an arbitrary number of real parameters. PB NATL ACAD SCI UKRAINE SN 1815-0659 YR 2021 FD 2021 LK http://hdl.handle.net/10498/24755 UL http://hdl.handle.net/10498/24755 LA eng NO MAGF would like to thank the Max-Planck-Institute for Mathematics in the Sciences, Leipzig (Germany), where some of her work took place. DGU acknowledges support from the Spanish MICINN under grants PGC2018-096504-B-C33 and RTI2018-100754-B-I00 and the European Union under the 2014-2020 ERDF Operational Programme and by the Department of Economy, Knowledge, Business and University of the Regional Government of Andalusia (project FEDER-UCA18-108393). DS Repositorio Institucional de la Universidad de Cádiz RD 10-may-2026