@article {2004, title = {Bifurcation of free vibrations for completely resonant wave equations}, journal = {Boll. Unione Mat. Ital. Sez. B 7 (2004) 519-528}, number = {SISSA;27/2004/M}, year = {2004}, abstract = {We prove existence of small amplitude, 2 pi/omega -periodic in time solutions of completely resonant nonlinear wave equations with Dirichlet boundary conditions for any frequency omega belonging to a Cantor-like set of positive measure and for a generic set of nonlinearities. The proof relies on a suitable Lyapunov-Schmidt decomposition and a variant of the Nash-Moser Implicit Function Theorem.}, url = {http://hdl.handle.net/1963/2245}, author = {Massimiliano Berti and Philippe Bolle} }