Equilibrium and nonequilibrium statistical mechanics of a nonlinear model of DNA

Experimental and theoretical studies indicate that the hydrogen bond stretch mode dominates DNA dynamics close to denaturation temperatures. We analyze a simplified model for DNA which retains only this (nonlinear) degree of freedom. The dynamics and thermodynamics of the system are discussed. In particular, the analytical and numerical results do not exhibit a melting transition but instead a state of pseudo-equilibrium distinct from the state expected from equilibrium thermodynamics. Finally numerical results show that energy transport is unlikely at biological temperatures.