Renormalization of the $3D$ $SU(N)$ scalar energy-momentum tensor using the Wilson flow

Abstract

In the holographic approach to cosmology, cosmological observables are described in terms of correlators of a three-dimensional boundary quantum field theory. As a concrete model, we study the $3D$ massless $SU(N)$ scalar matrix field theory with a ${\varphi }^4$ interaction. On the lattice, the energy-momentum tensor (EMT) in this theory can mix with the operator ${\varphi }^2$. We utilize the Wilson Flow to renormalize the EMT on the lattice, and present numerical results for the mixing coefficient for $N=2$. Obtaining the renormalized EMT will allow us to make predictions for the CMB power spectra in the regime where the dual QFT is non-perturbative.

Comments: 10 pages, 3 figures, presented at the 38th International Symposium on Lattice Field Theory - LATTICE2021 - 26-30 July, 2021, Massachusetts Institute of Technology