SYK-like Tensor Models on the Lattice
Prithvi Narayan, Junggi Yoon
TL;DR
<3-5 sentence high-level summary>This paper develops a lattice realization of SYK-like tensor models, focusing on KT chain, GW, and generalized GW constructions, and extends to rank-D variants. By summing melonic two-point diagrams and ladder four-point diagrams across Cooper, Pillow, and Tetrahedron channels, it derives kernel structures, spectra, and chaos properties at large N and strong coupling, with explicit expressions for diffusion and Lyapunov exponents. A key finding is that Cooper-channel dynamics saturate the chaos bound (λ_L = 2π/β) in KT and GW variants, while Pillow channels remain non-chaotic at leading order and reveal subleading chaotic behavior and a rich operator spectrum. The analysis generalizes to rank-D tensor models, showing analogous chaotic behavior and identifying next-to-subleading 1/N corrections for D>5, consistent with an emergent Schwarzian-like effective action. These results clarify how lattice structure and color contractions shape chaotic and transport properties in SYK-like tensor systems and open avenues for further rank-D and non-melonic explorations.
Abstract
We study large $N$ tensor models on the lattice without disorder. We introduce techniques which can be applied to a wide class of models, and illustrate it by studying some specific rank-3 tensor models. In particular, we study Klebanov-Tarnopolsky model on lattice, Gurau-Witten model (by treating it as a tensor model on four sites) and also a new model which interpolates between these two models. In each model, we evaluate various four point functions at large $N$ and strong coupling, and discuss their spectrum and long time behaviors. We find similarities as well as differences from SYK model. We also generalize our analysis to rank-$D$ tensor models where we obtain analogous results as $D=3$ case for the four point functions which we computed. For $D>5$, we are able to compute the next-to-subleading ${1 \over N}$ corrections for a specific four point function.
