“…In particular, there are at least four, albeit related, points of view that could connect the h coefficients of equations (2.9) and (3.12), other series coefficients and the sum S 2 , with the theories of diffusion, Brownian motion and random walk. Underlying much of this connection is the fact that a Jacobi theta function (Coffey 2002), a solution of the heat equation, provides a basis for a (Mellin transform) representation of the Riemann xi function (Riemann 1859;Biane et al 2001;Coffey 2005aCoffey , 2007c). …”