Bateman transform

In the mathematical study of partial differential equations, the Bateman transform is a method for solving the Laplace equation in four dimensions and wave equation in three by using a line integral of a holomorphic function in three complex variables. It is named after the mathematician Harry Bateman, who first published the result in (Bateman 1904).

The formula asserts that if ƒ is a holomorphic function of three complex variables, then

${\displaystyle \phi (w,x,y,z)=\oint _{\gamma }f{\big (}(w+ix)+(iy+z)\zeta ,(iy-z)+(w-ix)\zeta ,\zeta {\big )}\,d\zeta }$

is a solution of the Laplace equation, which follows by differentiation under the integral. Furthermore, Bateman asserted that the most general solution of the Laplace equation arises in this way.