Gauge Threshold Corrections for Local String Models (NOTE UNUSUAL DAY)

by Joe Conlon (Oxford Univ.)

Monday 30 Mar 2009, 14:00 → 15:00 Europe/Zurich

TH Theory Conference Room (CERN)

I study gauge threshold corrections for?local models?in which the 4d Planck scale can in principle be decoupled from the string scale. Examples of such models are local GUTs in F-theory/IIB or branes at singularities. Consistency with the effective supergravity implies the unification scale should be enhanced to R M_s from the naive M_s. For the calculable case of D3s at singularities a direct string computation agrees with this result. The appearance of the bulk radius arises from RR tadpoles sourced by the local model and cancelled in the bulk.