Solution for a Space-time Fractional Diffusion Equation

This work focuses on investigating the solutions for a generalized fractional diffusion equation. This equation presents space and time fractional derivatives, includes an absorbent term and a linear external force, takes a time-dependent diffusion coefficient into account, and subjects to the natural boundaries and the general initial condition. We obtain explicit analytical expressions in terms of the Fox H functions for the probability distribution. In addition, we analyze the first passage time and the second movement distribution for the case characterized by the absence of absorbent term and external force for a semi-infinite interval with absorbing boundary condition.