All in the Family: the quintessential kinship between Inflation and Dark Energy

Abstract

A unified dynamical model of dark energy and inflation is presented, in which both phenomena are driven by axion-like fields-quintessences-of spontaneously broken global $U(1)_A$'s symmetries whose potentials are induced by instantons of the QCD gauge group $SU(3)_c$ for inflation and of a new strongly interacting gauge group $SU(2)_Z$ for dark energy. It is shown that $SU(3)_c$ and $SU(2)_Z$ fit snugly into a unified gauge group $SU(5)_Z$, {\em Ischyr$\acute{o}$s Unification Theory} or {\em IUT}, which is spontaneously broken down to $SU(3)_c \times SU(2)_Z \times U(1)_X$. A judicious choice of $SU(5)_Z$ representations leads to the $SU(3)_c$ and $SU(2)_Z$ couplings growing strong at $\Lambda_{QCD} \sim 200 \mev$ and $\Lambda_Z \sim 10^{-3} eV$ respectively. The model predicts particles carrying $SU(2)_Z$ quantum numbers which can be searched for at colliders such as the LHC and which, as a result, might indirectly reveal the nature of dark energy and perhaps inflation in a laboratory. In addition, the fermionic spectrum of the model contains a possible candidate for dark matter.