Lévy: step ~ |r|^{-(1+α)}
α=2: Gaussian (CLT)
α<2: heavy-tailed, infinite variance
α<1: infinite mean jump length
P(|X|>x) ~ x^{-α}
MSD ~ t^{2/α} (superdiffusion)
α=2: Gaussian (CLT)
α<2: heavy-tailed, infinite variance
α<1: infinite mean jump length
P(|X|>x) ~ x^{-α}
MSD ~ t^{2/α} (superdiffusion)