Quantum bounds from fluctuation-dissipation relations*

One may express the out of time order correlators (OTOC) as two-point functions in a replicated space. The quantum bound to chaos derives then from the usual quantum fluctuation-dissipation relations (FDT). Motivated by this result, I will discuss how the quantum FDT acts as a blurring (on a Planckian timescale) of general two-point functions expressed in the time-domain, thus imposing bounds on their rate of change.