  As recently proposed, the long-time behavior of equilibrium time-correlation
functions for one-dimensional systems are expected to be captured by a
nonlinear extension of fluctuating hydrodynamics. We outline the predictions
from the theory aimed at the comparison with molecular dynamics. We report on
numerical simulations of a fluid with a hard-shoulder potential and of a
hard-point gas with alternating masses. These models have in common that the
collision time is zero and their dynamics amounts to iterating collision by
collision. The theory is well confirmed, with the twist that the non-universal
coefficients are still changing at longest accessible times.
