We present the similarities and differences between one-dimensional (1D) an
d two-dimensional (2D) spatially localized, time periodic solutions in disc
rete nonlinear Hamiltonian systems. In particular, the types of modes their
stability and their bifurcations are presented. We find that two dimension
s, apart from offering an additional mode compared with one dimension, exhi
bit a much richer stability scenario. This is analyzed in detail using cont
inuation techniques and linear stability analysis. (C) 2001 IMACS. Publishe
d by Elsevier Science B.V. All rights reserved.