Stability of subsonic and supersonic solitons in DNA

In the present work, we rely on the helicoidal Peyrard–Bishop model of DNA and use a continuum approximation to solve a crucial dynamical equation of motion. This brings about kink solitary waves moving along the chain. We demonstrate that viscosity is crucial, as no waves are stable when viscosity is neglected. Furthermore, we show that, when viscosity is taken into consideration, the subsonic kink solitons are stable, while the supersonic ones are not.