Warped products and the Reissner-Nordstr\"{o}m-AdS black hole
  We study a multiply warped product manifold associated with the Reissner-Nordstrom-AdS metric to investigate the physical properties inside the black hole event horizons. Our results include various limiting geometries of the RN, Schwarzschild--AdS and Schwarzschild space-times, through the successive truncation procedure of parameters in the original curved space. 
Soon-Tae Hong, Jaedong Choi, Young-Jai Park