Phase Diagram of Gross-Neveu Model at Finite Temperature, Density and   Constant Curvature
  We discuss a phase structure of chiral symmetry breaking in the Gross-Neveu model at finite temperature, density and constant curvature. The effective potential is evaluated in the leading order of the $1/N$-expansion and in a weak curvature approximation. The third order critical line is found on the critical surface in the parameter space of temperature, chemical potential and constant curvature. 
S. Kanemura and H.-T. Sato