Gauge and moduli hierarchy in a multiply warped braneworld scenario
  A generalized Randall sundrum model in six dimensional bulk is studied in presence of non-flat 3-branes at the orbifold fixed points. The warp factors for this model is determined in terms of multiple moduli and brane cosmological constant. We show that the requirements of a vanishingly small cosmological constant on the visible brane along with non-hierarchical moduli, each with scale close to Planck length, lead to a scenario where the 3-branes can not have any intermediate scale and have energy scales either close to Tev or close to Planck scale. Such a scenario can address both the gauge hierarchy as well as fermion mass hierarchy problem in standard model. Thus simultaneous resolutions to these problems are closely linked with the near flatness condition of our universe without any intermediate hierarchical scale for the moduli. 
Ashmita Das and Soumitra SenGupta
hep-th gr-qc hep-ph