FM 99-4 V 1.1 (last updated: feb 99) Authors: L. Chierchia, E. Valdinoci Title: A note on the construction of Hamiltonian trajectories along heteroclinic chains Abstract: We provide a short, simple proof of the existence of Hamiltonian trajectories arbitrarily close to a given chain of heteroclinic orbits connecting ``codimension-one, KAM, whiskered tori". Keywords: Arnold diffusion, heteroclinic chains, KAM -------- L.C.: Dipartimento di Matematica, Universita' Roma Tre, Largo S. Leonardo Murialdo 1, 00146 Roma (Italia) E.V.: Department of Mathematics, The University of Texas at Austin, TX 78712-1082 (USA) --------- e-mail users: luigi@matrm3.mat.uniroma3.it enrico@math.utexas.edu tel. 6-54888235, fax 6-54888072