Sources for Gravitational Fields and Cosmology
  Analysis of the gravitational source for the Schwarzschild metric indicates that the time and the radial components of the energy momentum tensor are equal. Imposing such a condition on cosmology, we propose a cosmological model that is a modification of the Friedman-Robertson-Walker (FRW) universe. An accelerating universe emerges as a natural consequence of this ansatz. 
Yukio Tomozawa