Subdiffusion with External Time Modulation

A subdiffusion process, similar to a Zeldovich-Kompaneets heat conduction process, is defined by a nonlinear diffusion equation in which the diffusion coefficient takes the form D=a(t)f^n, where a=a(t) is an external time modulation, n is a positive constant, and f=f(x, t) is a solution to the nonlinear diffusive equation. It is shown that a Zeldovich-Kompaneets solution satisfies the subdiffusion equation if a=a(t) is replaced by the mean value of a. Also, a solution to the subdiffusion equation is constructed that may be useful in description of biological, social, and financial processes.