Abstract
Dynamical theory of soliton excitations in deoxyribonucleic acid (DNA) double helices has been studied by a revised Hamiltonian in which the dipole-dipole interaction and the dipoleinduced-dipole interaction between two bases in a complementary base pair are taken into account in addition to the hydrogen-bond energy. The motion equations of bases are a set of coupled sine-Gordon equations. The soliton solutions of these equations are studied in detail and the results are compared with the experimental data in the H-D exchange measurements of DNA chains.