String Theory seminar - Juan Pedraza Seminar

Holographic theories with classical gravity duals are maximally chaotic, i.e. they saturate the universal bound on the rate of growth of chaos. It is interesting to ask whether this property is true only for leading large N correlators or if it can show up elsewhere. We consider the simplest setup to tackle this question: a Brownian particle coupled to a thermal ensemble. This system is dual to a long string stretching between the event horizon of an AdS black brane and its asymptotic boundary. We find that the four-point out-of-time-order correlator that diagnoses chaos initially grows at an exponential rate that saturates chaos bound, however, the scrambling time is parametrically smaller than for plasma excitations. Our result shows that, at least in certain cases, maximal chaos can be attained in the probe sector without the explicit need of gravitational degrees of freedom.