Exact Solution of a Linear Wave Equation in Cosmological General   Relativity
  A linear second order wave equation is presented based on cosmological general relativity, which is a space-velocity theory of the expanding Universe. The wave equation is shown to be exactly solvable, based on the Gaussian hypergeometric function. 
Firmin J. Oliveira (Joint Astronomy Centre, Hilo, Hawai`i, U.S.A.)