Logarithmic derivative of the Euler Γ function in Clifford analysis.
The logarithmic derivative of the Γ-function, namely the ψ-function, has numerous applications. We define analogous functions in a four dimensional space. We cut lattices and obtain Clifford-valued functions. These functions are holomorphic cliffordian and have similar properties as the ψ-function. These new functions show links between well-known constants: the Eurler gamma constant and some generalisations, ζ(2), ζ(3). We get also the Riemann zeta function and the Epstein zeta functions.