Renormalizable Enhanced Tensor Field Theory: The quartic melonic case

TL;DR

This paper analyzes the renormalizability of enhanced tensor field theories with quartic melonic interactions, identifying conditions for their renormalizability and exploring their phase structure in the large N limit.

Contribution

It provides a multi-scale renormalization analysis of enhanced tensor field theories, discovering a 2-parameter family of just-renormalizable models and characterizing their divergence properties.

Findings

Identified conditions for all-order renormalizability.

Discovered a 2-parameter space of just-renormalizable models.

Analyzed divergence structure of exotic models with finite four-point but divergent two-point functions.

Abstract

Amplitudes of ordinary tensor models are dominated at large $N$ by the so-called melonic graph amplitudes. Enhanced tensor models extend tensor models with special scalings of their interactions which allow, in the same limit, that the sub-dominant amplitudes to be "enhanced", that is to be as dominant as the melonic ones. These models were introduced to explore new large $N$ limits and to probe different phases for tensor models. Tensor field theory is the quantum field theoretic counterpart of tensor models and enhanced tensor field theory enlarges this theory space to accommodate enhanced tensor interactions. We undertake the multi-scale renormalization analysis for two types of enhanced quartic melonic theories with rank $d$ tensor fields $\phi: (U(1)^{D})^{d} \to \mathbb{C}$ and with interactions of the form $p^{2a}\phi^4$ reminiscent of derivative couplings expressed in momentum space. Scrutinizing the degree of divergence of both theories, we identify generic conditions for their renormalizability at all orders of perturbation. For a first type of theory, we identify a 2-parameter space of just-renormalizable models for generic $(d,D)$. These models have dominant non-melonic four-point functions. Finally, by specifying the parameters, we detail the renormalization analysis of a second type of model. Lying in between just- and super-renormalizability, that model is more exotic: all four-point amplitudes are convergent, however it exhibits an infinite family of divergent two-point amplitudes.