Resumen: The properties of a nonlinear oscillator with an additional term kg/x2, character- izing the isotonic oscillator, are studied. The nonlinearity affects to both the kinetic term and the potential and combines two nonlinearities associated to two parameters, ¿ and kg, in such a way that for ¿ = 0 all the characteristics of of the standard isotonic system are recovered. The first part is devoted to the classical system and the sec- ond part to the quantum system. This is a problem of quantization of a system with position-dependent mass of the form m(x) = 1/(1 - ¿x2), with a ¿-dependent non- polynomial rational potential and with an additional isotonic term. The Schr ¨odinger equation is exactly solved and the (¿,kg)-dependent wave functions and bound state energies are explicitly obtained for both ¿ < 0 and ¿ > 0. Idioma: Inglés DOI: 10.1063/1.4892084] Año: 2014 Publicado en: JOURNAL OF MATHEMATICAL PHYSICS 55, 8 (2014), 082108 (12 pp.) ISSN: 0022-2488 Factor impacto JCR: 1.243 (2014) Categ. JCR: PHYSICS, MATHEMATICAL rank: 27 / 54 = 0.5 (2014) - Q2 - T2 Financiación: info:eu-repo/grantAgreement/ES/DGA/E24-1 Financiación: info:eu-repo/grantAgreement/ES/MICINN/MTM2012-33575 Tipo y forma: Artículo (PostPrint) Área (Departamento): Área Física Teórica (Dpto. Física Teórica)