The brane world based on the 6D gravitational model is examined. It is regarded as a higher dimensional version of the 5D model by Randall and Sundrum >. The obtained analytic solution is checked by the numerical method. The mass hierarchy is examined. Especially the { \it geometrical see-saw} mass relation, between the Planck mass, the cosmological constant, and the neutrino mass, is suggested. Comparison with the 5D model is made.
Categories: gr-qc hep-th