Possible Propagating Intrinsic Localized Vibrational Modes for One-Dimensional Klein–Gordon Lattice*

All possible existed propagating intrinsic localized vibrational modes for the discrete Klein-Gordon lattice are obtained analytically in the whole omega(q) space of the system by means of the so-called semidiscrete approximation, with which the carrier wave is treated explicitly while the envelope is described in the continuum approximation. Our investigation shows that, in general, both the pulse-like and kink (antikink) envelope types of the vibrational modes for the system can occur with certain carrier wavenumbers and frequencies in the separated parts of the omega(q) space. And the propagating velocity of the pulse-like modes is either subsonic or nearsonic, and that of the kink (antikink) modes is either subsonic or supersonic. Our results are similar to or consistent with some results for Klein-Gordon lattice model or other related nonlinear lattice systems by some different methods.