Solitary waves in helicoidal models of DNA dynamics

We analyze travelling solitary wave solutions in the Barbi-Cocco-Peyrard and in a simplified version of the Cocco-Monasson models of nonlinear DNA dynamics. We identify conditions to be satisfied by parameters for such solutions to exist, and provide first order ODEs whose solutions give the required solitary waves; these are not solvable in analytical terms, but are easily integrated numerically.