Agradecimientos:
We acknowledge support by the U .S. Department of Energy. A. S. is partially supported by the Comisión Interministerial de Ciencia y Tecnologia (CICyT) of Spain under Grant No. MAT90-0544
A spatially periodic perturbation can lead to a breakup of large-amplitude sine-Gordon breathers
into kink and anti kink solutions, each oscillating around a minimum of the perturbing potential. This
behavior can be understood by studying the effective potentiA spatially periodic perturbation can lead to a breakup of large-amplitude sine-Gordon breathers
into kink and anti kink solutions, each oscillating around a minimum of the perturbing potential. This
behavior can be understood by studying the effective potential experienced by the breather (bound
kink-antikink) or the (free) kink-antikink solution as long as kink and antikink are sufficiently far
apart. The resulting kinks and antikinks move independently and nearly radiationlessly in the
presence of the perturbation and can travel arbitrarily far for sufficiently large initial kinetic energy.
Upon interacting with each other they are strongly affected by the perturbation, lose energy by
radiating, and can end in a bound state having the character of a distorted breather.[+][-]