Speaker: B Sánchez-Rey (slides 420 kb)
With G James, FR Romero and A Alvarez

Abstract: We study the existence and linear stability of bright and dark breathers in one-dimensional FPU lattices, testing the range of validity of a recent breathers existence proof [G. James, C. R. Acad. Sci. Paris, 332, Ser. 1 Math, 332, 581 (2001)] using numerical computations. Approximate analytical expressions for small amplitude bright and dark breathers fit very well with exact numerical solutions. We also study numerically large amplitude breathers. For a class of asymmetric FPU potentials we find an energy threshold for the existence of exact discrete breathers. We also investigate bright and dark breathers superposed on a uniformly stressed static configuration.

NLDD 2004: Nonlinear Double Day on Macroscopic Effects of Anharmonic Excitations, Sevilla, Spain, 17-18 May 2004.