Unified theory of cell diffusion coefficients

This paper introduces a new operating definition of the radial diffusion coefficient for a cell; the definition clarifies what gross flux must be used, and respects Selengut's equivalence principle. The coefficient thus obtained is shown to be equivalent to the cell edge- flux normalized value of Benoist's diffusion coefficient. A complete account of the calculation of absorption- related corrections to the mean- space diffusion coefficient is given, along with a corrected version of the relationship between such quantity and the tilted flux in a lattice. A generalized equivalence method and close approximations to some Benoist functions are given for practical calculations.