Grand Unification at About 4 TeV

Abstract

Use of the AdS/CFT correspondence to arrive at phenomenological gauge field theories is dicussed, focusing on the orbifolded case without supersymmetry. An abelian orbifold with the finite group $Z_p$ can give rise to a $G=SU(N{)}^p$ gauge group with chiral fermions and complex scalars in different bi-fundamental representations of $G$. The precision measurements at the $Z$ resonance suggest the values $p=12$ and $N=3$, and a unifications scale $M_U\sim 4$ TeV. Robustness and predictivity of such grand unification is discussed.

11 pages latex, one eps figure. Plenary Talk at SUGRA 20, Northeastern University, March 2003