“…is a modification of sub-diffusion and has attracted a lot attention by many researchers in the last two decades. In the literature, this equation relates to the initial works [13,14,[20][21][22][23][24], and provides new mathematical and theoretical aspects for studying of the physical and natural sciences in different cases of b(σ) and fractional operators using the analytical and numerical methods [6,8,9,18,25,27,34,35,44,45,47,49,50].…”