Large-$N$ limit of $O(N)^3$-invariant general sextic tensor model
Gaetan Bardy, Thomas Krajewski, Thomas Muller, Adrian Tanasa
TL;DR
This work extends the large-$N$ analysis to the $O(N)^3$-invariant sextic tensor model with all eight invariant bubbles, identifying the full set of dominant graphs in the $1/N$ expansion. By employing an adapted intermediate-field method (real and complex fields) and cyclotomic jacket analysis, the authors reduce sextic interactions to a quartic sector (tetrahedron and pillow) and demonstrate that wheel interactions cannot mix with other sextics in dominant graphs. They systematically classify dominant graphs for each interaction, uncover new mixed-bubble structures, and discover four fundamental dominant graphs that mix multiple interactions, all with vanishing degree. The results reveal a richer large-$N$ diagrammatics than in prior tensor models, including infinite families of dominant graphs, and set the stage for deeper renormalization and Schwinger-Dyson analyses in this broader invariant class.
Abstract
We study a sextic tensor model where the interaction terms are given by all $O(N)^3$-invariant bubbles. The class of invariants studied here is thus a larger one that the class of the $U(N)^3$-invariant sextic tensor model. We implement the large $N$ limit mechanism for this general model and we explicitly identify the dominant graphs in the $1/N$ expansion. This class of dominant graphs contains tadpole graphs, melonic graphs but also new types of tensor graphs. Our analysis adapts the tensorial intermediate field method, previously applied only to the prismatic interaction, to all connected sextic interactions except the wheel interaction, which we treat separately using a cycle analysis.
