The SYK model consists of N≫1 fermions in 0+1 dimensions with a random, all-to-all quartic interaction. Recently, Kitaev has found that the SYK model is maximally chaotic and has proposed it as a model of holography. We solve the Schwinger-Dyson equation and compute the spectrum of two-particle states in SYK, finding both a continuous and discrete tower. The four-point function is expressed as a sum over the spectrum. The sum over the discrete tower is evaluated.
@article{arxiv.1601.06768,
title = {The Spectrum in the Sachdev-Ye-Kitaev Model},
author = {Joseph Polchinski and Vladimir Rosenhaus},
journal= {arXiv preprint arXiv:1601.06768},
year = {2016}
}