Nonhyperbolic behavior in the thermostated Lorentz gas.


We show that nonhyperbolic behavior in the length-2 periodic orbits of the thermostated random Lorentz gas occurs only at field strengths greater than unity. For the thermostatted periodic Lorentz gas the range of fields is reduced further due to pruning. Stability analysis shows that there are three classes of period-2 orbits: elliptic orbits and two… (More)