Long range SYK model and boundary SYK model

Abstract

We study a class of long-range solvable models in IR limit which corresponds to a one-dimensional long-range conformal manifold. This class of long-range model can be interpreted as the non-unitary interpolation between the Sachdev-Ye-Kiteav-like model and the free theory. We investigate the chaos and information scrambling of the model by analyzing its out-of-time order correlators. We find the suppression of the Lyapunov exponent by the long-range interaction and a slowdown in butterfly velocity in the emergent light cone which can be interpreted as the contribution from the anomalous dimension of the stress tensor in the spectrum. We further study a Yukawa-SYK model located in a 3-dimensional boundary with a free field living in a 4-dimensional bulk. The boundary IR spectrum of the model contains a tower of the spinning operators protected by the higher spin symmetry of the bulk. We evaluate the central charge and the Lyapunov exponent of the model.

12 pages, 10 figures, comments are welcome