Gravitons and the Drell-Hearn-Gerasimov Sum Rule -- Support for Large Extra Dimensions?
Haim Goldberg · arXiv (Cornell University) · 1999
One-loop diagrams containing a graviton provide a finite contribution to the anomalous magnetic moment aℓ of a lepton, whether or not the graviton propagates in n large extra compact dimensions. In the present work, the tree graph photoproduction of a graviton, integrated up to the string scale, is shown to violate the Drell-Hearn-Gerasimov sum rule for a2 ℓ. It is then seen that for n> 0, the Regge behavior for an appropriate open string Compton amplitude above the string scale could restore the validity of the sum rule. However, for the case A renewed interest in quantum gravity has been catalyzed by the innovative recent proposal [1] that the gravitational sector lives in an expanded (4 + n)-dimensional spacetime, with the extra n dimensions compactified on surfaces with characteristic sizes as large as a millimeter. For compactification on an n-torus, the fundamental