  Lattice Boltzmann simulations of liquid-gas systems are believed to be
restricted to modest density ratios of less than 10. In this article we show
that reducing the speed of sound and, just as importantly, the interfacial
contributions to the pressure allows lattice Boltzmann simulations to achieve
high density ratios of 1000 or more. We also present explicit expressions for
the limits of the parameter region in which the method gives accurate results.
There are two separate limiting phenomena. The first is the stability of the
bulk liquid phase. This consideration is specific to lattice Boltzmann methods.
The second is a general argument for the interface discretization that applies
to any diffuse interface method.
