Dynamically induced topological inflation

Abstract

We propose an inflation model in which the inflationary era is driven by the strong dynamics of $Sp(2)$ gauge theory. The quark condensation in the confined phase of $Sp(2)$ gauge theory generates the inflaton potential comparable to the energy of the thermal bath at the time of phase transition. Afterwards, with a super-Planckian field value at the global minimum, the inflation commences at a false vacuum region lying between true vacuum regions and hence the name ``topological inflation.'' Featured by the huge separation between the scale of the false vacuum ($V(0{)}^{1/4}\ensuremath{\sim}{10}^{15}\text{ }\text{ }\mathrm{GeV}$) and the field value at the global minimum (${\ensuremath{\phi}}_{\mathrm{min}}\ensuremath{\sim}{M}_{P}$), the model can be consistent with cosmic microwave background (CMB) observables without suffering from the initial condition problems. Crucially, this is achieved only with some mild tuning of parameters in $V(\ensuremath{\phi})$. In addition to $Sp(2)$, this model is based on an anomaly free ${Z}_{6R}$ discrete $R$ symmetry. Remarkably, while all parameters are fixed by CMB observations, the model predicts a hierarchy of energy scales including the inflation scale, supersymmetry-breaking scale, R-symmetry breaking scale, Higgsino mass and the right-handed neutrino mass given in terms of the dynamical scale of $Sp(2)$.