  We study fluctuations of particle number in the presence of critical point by
utilizing molecular dynamics simulations of the classical Lennard-Jones fluid
in a periodic box. The numerical solution of the $N$-body problem naturally
incorporates all correlations, exact conservation laws, and finite size
effects, allowing us to study the fluctuation signatures of the critical point
in a dynamical setup. We find that large fluctuations associated with the
critical point are observed when measurements are performed in coordinate
subspace, but, in the absence of collective flow and expansion, are essentially
washed out when momentum cuts are imposed instead. We put our findings in the
context of event-by-event fluctuations in heavy-ion collisions.
