Speaker
Description
We investigate the (inhomogeneous) phase structure of the Gross-Neveu model in a noninteger number of spatial dimensions 1 <= d < 3 in the limit of an infinite number of fermion species at (non)zero chemical potential and nonzero temperature.
The phase diagram of the Gross-Neveu model in 1 <= d < 3 spatial dimensions is well known under the assumption of spatially homogeneous condensation with both a symmetry broken and a symmetric phase present for all spatial dimensions. In d = 1 one additionally finds an inhomogeneous phase, where the order parameter, the condensate, is varying in space. Similarly, phases of spatially varying condensates are also found in the Gross-Neveu model in d = 2 and d = 3, as long as the theory is not fully renormalized, i.e., in the presence of a regulator. For d = 2, one observes that the inhomogeneous phase vanishes, when the regulator is properly removed (which is not possible for d = 3 without introducing additional parameters).
In the present work, we use the stability analysis of the symmetric phase to study the presence (for 1 <= d < 2) and absence (for 2 <= d < 3) of these inhomogeneous phases and the related moat regimes in the fully renormalized Gross-Neveu model in the mu-T-plane. We also discuss the relation between "the number of spatial dimensions" and "studying the model with a finite regulator" as well as the possible consequences for the limit d -> 3 and effective models for QCD.
