Abstract
In order to introduce the Riemann-Liouville (RL) and Caputo (C) fractional potentials, we use the Laplace transform and the Mittag-Leffler function to solve, in infinite dimension, the C time fractional diffusion equation and RL time fractional diffusion equation with respect to the number operator acting on a distribution space. Then, we show that these fractional potentials verify some fractional Poisson equations and some regularity properties.