Cobos Díaz, FernandoCordeiro, José MaríaMartínez, Antón2023-06-202023-06-2019990041-7084https://hdl.handle.net/20.500.14352/57312The authors investigate the behaviour of bilinear operators under interpolation by the methods associated to polygons. These methods, working with N-tuples (N _ 3) of Banach spaces instead of couples, were introduced by F. Cobos and J. Peetre [Proc. Lond. Math. Soc., III. Ser. 63, 371-400 (1991; Zbl 0727.46053)]. The main properties of methods defined by polygons are summarized and then a bilinear interpolation theorem for a combination of the K- and J-methods is established. Another bilinear interpolation theorem for the J-method is given and a counterexample shows that a similar result fails for the K-method. The final part contains an application to interpolation of operator spaces starting from Banach lattices.engjournal articlerestricted access519.6Behaviour of bilinear operators under interpolationMethods defined by polygonsCombination of the K- and J-methodsAnálisis numérico1206 Análisis Numérico