Thin accretion disk around a Kaluza-Klein black hole with squashed   horizons
  We study the accretion process in the thin disk around a squashed Kaluza-Klein black hole and probe the effects of the extra dimensional scale $\rho_0$ on the physical properties of the disk. Our results show that with the increase of the parameter $\rho_0$, the energy flux, the conversion efficiency, the radiation temperature, the spectra luminosity and the spectra cut-off frequency of the thin accretion disk decrease, but the inner border of the disk increases. This implies that the extra dimension scale imprints in the mass accretion process in the disk. 
Songbai Chen, Jiliang Jing
gr-qc astro-ph.CO hep-th