Three methods for the study of semilinear equations at resonance
Volume 66 / 1993
Colloquium Mathematicum 66 (1993), 109-12 DOI: 10.4064/cm-66-1-109-12
Three methods for the study of the solvability of semilinear equations with noninvertible linear parts are compared: the alternative method, the continuation method of Mawhin and a new perturbation method -. Some extension of the last method and applications to differential equations in Banach spaces are presented.