We discuss the critical properies of the three-dimensional Gross-Neveu model
at nonzero temperature and nonzero chemical potential. We also present
numerical and analytical results for the in-medium interaction due to scalar
meson exchange. Further, we discuss in-medium modifications of mesonic
dispersion relations and wavefunctions.Comment: 9 pages, 5 figures, Contribution to Workshop on Finite Density QCD at
Nara, Japan, July 10-12 200