@article {2008,
	title = {Forced Vibrations of a Nonhomogeneous String},
	journal = {SIAM J. Math. Anal. 40 (2008) 382-412},
	number = {SISSA;36/2006/M},
	year = {2008},
	abstract = {We prove existence of vibrations of a nonhomogeneous string under a nonlinear time periodic forcing term in the case in which the forcing frequency avoids resonances with the vibration modes of the string (nonresonant case). The proof relies on a Lyapunov-Schmidt reduction and a Nash-Moser iteration scheme.},
	doi = {10.1137/060665038},
	url = {http://hdl.handle.net/1963/2643},
	author = {P Baldi and Massimiliano Berti}
}
@article {2006,
	title = {Forced vibrations of wave equations with non-monotone nonlinearities},
	journal = {Ann. Inst. H. Poincar{\'e} Anal. Non Lin{\'e}aire 23 (2006) 439-474},
	number = {arXiv.org;math/0410619v1},
	year = {2006},
	abstract = {We prove existence and regularity of periodic in time solutions of completely resonant nonlinear forced wave equations with Dirichlet boundary conditions for a large class of non-monotone forcing terms. Our approach is based on a variational Lyapunov-Schmidt reduction. It turns out that the infinite dimensional bifurcation equation exhibits an intrinsic lack of compactness. We solve it via a minimization argument and a-priori estimate methods inspired to regularity theory of Rabinowitz.},
	doi = {10.1016/j.anihpc.2005.05.004},
	url = {http://hdl.handle.net/1963/2160},
	author = {Massimiliano Berti and Luca Biasco}
}
@article {2002,
	title = {Fast Arnold diffusion in systems with three time scales},
	journal = {Discrete Contin. Dyn. Syst. 8 (2002) 795-811},
	number = {SISSA;21/2001/M},
	year = {2002},
	publisher = {American Institute of Mathematical Sciences},
	abstract = {We consider the problem of Arnold Diffusion for nearly integrable partially isochronous Hamiltonian systems with three time scales. By means of a careful shadowing analysis, based on a variational technique, we prove that, along special directions, Arnold diffusion takes place with fast (polynomial) speed, even though the \\\"splitting determinant\\\" is exponentially small.},
	url = {http://hdl.handle.net/1963/3058},
	author = {Massimiliano Berti and Philippe Bolle}
}
@article {2002,
	title = {A functional analysis approach to Arnold diffusion},
	journal = {Ann. Inst. H. Poincare Anal. Non Lineaire 19 (2002) 395-450},
	year = {2002},
	publisher = {Elsevier},
	abstract = {We discuss in the context of nearly integrable Hamiltonian systems a functional analysis approach to the \\\"splitting of separatrices\\\" and to the \\\"shadowing problem\\\". As an application we apply our method to the problem of Arnold Diffusion for nearly integrable partially isochronous systems improving known results.},
	doi = {10.1016/S0294-1449(01)00084-1},
	url = {http://hdl.handle.net/1963/3151},
	author = {Massimiliano Berti and Philippe Bolle}
}
