Large scale suppression of scalar power on a spatial condensation

We consider a deformed single-field inflation model in terms of three SO(3) symmetric moduli fields. We find that spatially linear solutions for the moduli fields induce a phase transition during the early stage of the inflation and the suppression of scalar power spectrum at large scales. This suppression can be an origin of anomalies for large-scale perturbation modes in the cosmological observation.

Figure 1

The graphs of the inflaton field $\phi (N)$ (left) and Hubble radius $1/H(N)$ (right). We set the pivot scale $k_0=0.05{\mathrm{Mpc}}^{-1}$ and $N_{*}=60$. We choose the initial condition as $a_i=1$, ${\phi }_i=16.5M_{\mathrm{P}}$, $\dot{{\phi }_i}=0$, $m=5.85\times 10^{-6}{M}_{\mathrm{P}}$, and $\alpha =10^2$.

Figure 2

The primordial power spectrum of curvature perturbation for the usual single-field model (dashed blue line) and the inflation model on the spatial condensation (solid red line).