Renormalization footprints in the phase diagram of the Grosse-Wulkenhaar model

Abstract

We construct and analyze the phase diagram of a self-interacting matrix field in two dimensions coupled to the curvature of the noncommutative truncated Heisenberg space. In the infinite size limit, the model reduces to the renormalizable Grosse-Wulkenhaar model. The curvature term proves crucial for the diagram’s structure. When turned off, the triple point collapses into the origin as matrices grow larger; when turned on, the triple point recedes from the origin proportionally to the coupling strength and the matrix size. The coupling attenuation that turns the Grosse-Wulkenhaar model into a renormalizable version of the φ4⋆ model cannot stop the triple point recession. As a result, the stripe phase escapes to infinity, removing the problems with UV/IR mixing.