Gauge coupling variation in brane models
Abstract
We consider the spacetime variation of gauge couplings in braneworld models induced by the coupling to a bulk scalar field. A variation is generated by the running of the gauge couplings with energy and a conformal anomaly while going from the Jordan to the Einstein frame. We indicate that the oneloop corrections cancel implying that one obtains a variation of the fine structure constant by either directly coupling the gauge fields to the bulk scalar field or having bulk scalar field dependent Yukawa couplings. Taking into account the cosmological dynamics of the bulk scalar field, we constrain the strength of the gauge coupling dependence on the bulk scalar field and relate it to modifications of gravity at low energy.
 Publication:

Physical Review D
 Pub Date:
 December 2003
 DOI:
 10.1103/PhysRevD.68.123519
 arXiv:
 arXiv:astroph/0306279
 Bibcode:
 2003PhRvD..68l3519P
 Keywords:

 98.80.Cq;
 11.25.Wx;
 Particletheory and fieldtheory models of the early Universe;
 String and brane phenomenology;
 Astrophysics;
 High Energy Physics  Phenomenology;
 High Energy Physics  Theory
 EPrint:
 4 pages, 1 figure