|Speaker||Talk Date||Talk Series|
|Pisin Chen (LeCosPA, Taiwan and KIPAC, Stanford)||21 October, 2009||Institute of Astronomy Seminars|
We suggest that the cosmological constant as implied by the dark energy be related to the well-known hierarchy between the Planck scale (10^19GeV) and the Standard Model scale (TeV). It is posited that the same brane-world setup to address this hierarchy problem may also address the smallness problem of the cosmological constant. Specifically, the various physical energy scales in the system, including the cosmological constant, are supposedly associated with the Planck mass through different powers of the 'gravity fine structure constant', alpha_G=M_SM/M_Pl. We provide a model based on the Randall-Sundrum geometry where SUSY-breaking is induced by the coupling between a Higgs field and the gravitino on the TeV brane. We show that the Casimir energy density of the system indeed conforms with the observed dark energy scale.