Table 1.

Characteristics of the Different Classes of Models Considered in This Work plus Fractional Brownian Motion

Model Class	Characteristic Timescale(s)	MSD	Propagator
Simple diffusion	no (self-similar)	linear	Gaussian
Fractional Brownian motion	no (self-similar)	power law	Gaussian (nonlinear time dependance of the variance)
CTRW	no (ensemble-averaged ACF self-similar), but aging produces non-self-similar time-averaged ACF	linear (time average), power law (ensemble average)	non-Gaussian
Two-component diffusion	Relaxation time, τc = 1/(k01 + k10)	linear	sum of two Gaussians well below τc, Gaussian well above
Diffusing diffusivity	Time required to explore diffusion space, τc = (DM − Dm)2/2d	linear	quasiexponential well below τc, Gaussian well above
Caged diffusion	Cage relaxation time, τc = L2/(6D), escape time τ′c = τc/p	linear well below τc and well above τ′c	Gaussian well below τc and well above τ′c
Obstructed diffusion	Average time before obstacle encounter, τc = L2/(6Dϕ2/3))	linear well below and well above τc	Gaussian well below and well above τc