De Luca, JaymeDrigo Filho, Elso [UNESP]Ponno, AntonioRuggiero, José Roberto [UNESP]2022-04-282022-04-282004-01-01Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics, v. 70, n. 2, p. 9-, 2004.1063-651Xhttp://hdl.handle.net/11449/225146We study energy localization on the oscillator chain proposed by Peyrard and Bishop to model DNA. We search numerically for conditions with initial energy in a small subgroup of consecutive oscillators of a finite chain and such that the oscillation amplitude is small outside this subgroup on a long time scale. We use a localization criterion based on the information entropy and verify numerically that such localized excitations exist when the nonlinear dynamics of the subgroup oscillates with a frequency inside the reactive band of the linear chain. We predict a mimium value for the Morse parameter [Formula presented] (the only parameter of our normalized model), in agreement with the numerical calculations (an estimate for the biological value is [Formula presented]). For supercritical masses, we use canonical perturbation theory to expand the frequencies of the subgroup and we calculate an energy threshold in agreement with the numerical calculations. © 2004 The American Physical Society.9engArtigo10.1103/PhysRevE.70.0262132-s2.0-42749100398