Recent numerical calculations have shown that the ground state of the
Gross-Neveu model at finite density is a crystal. Guided by these results, we
can now present the analytical solution to this problem in terms of elliptic
functions. The scalar potential is the superpotential of the non-relativistic
Lame Hamiltonian. This model can also serve as analytically solvable toy model
for a relativistic superconductor in the Larkin-Ovchinnikov-Fulde-Ferrell
phase.Comment: 5 pages, no figures, revtex; vs2: appendix with analytical proof of
self-consistency adde