Stringy effects in SYK scrambling

Abstract: 
It has been proposed that the exponential decay and subsequent power law saturation of out-of-time-order correlation functions can be universally described by collective 'scramblon' modes. We develop this idea from a path integral perspective and apply the formalism to the large-q SYK chain that is amenable to analytical treatment at finite coupling, away from maximal chaos. We identify the relevant scramblon modes, derive their effective action, and their coupling to operators, thus constructing an effective description of scrambling. The final results can be matched in detail to stringy corrections to the gravitational eikonal S-matrix in holographic CFTs, including a stringy Regge trajectory, bulk to boundary propagators, and multi-string effects that are unexplored holographically.

The talk is based on: Changha Choi, Felix M. Haehl, Márk Mezei & Gábor Sárosi , JHEP 03 (2023) 142