Free Cumulants and Full Eigenstate Thermalization from Boundary Scrambling
The authors introduce a solvable quantum model called boundary scrambling to analytically study higher-order out-of-time-order correlators (OTOCs). They show this model unifies eigenstate thermalization and random circuit predictions. By identifying a higher-order Markovian influence matrix, they provide exact expressions for correlations, revealing how structured dynamics lead to random behavior.