By constructing an Ising analogue of compact-star matter at subsaturation density we explored the effect of Coulomb frustration on the nuclear liquid-gas phase transition. Our conclusion is twofold. First, the range of temperatures where inhomogeneous phases form expands with increasing Coulomb-field strength. Second, within the approximation of uniform electron distribution, the limiting point upon which the phase-coexistence region ends does not exhibit any critical behavior. Possible astrophysics consequences and thermodynamical connections are discussed.

• Received 22 September 2006

DOI:https://doi.org/10.1103/PhysRevLett.98.131102