A Predictive Inflationary Scenario Without The Gauge Singlet

Abstract

We propose a new realization of the chaotic inflationary scenario in which the scalar field responsible for inflation also spontaneously breaks the underlying gauge symmetry at a superheavy scale $\sim 10^{15} - 10^{17}\; GeV$. A possible framework is provided by the superstring inspired gauge models, in which case several predictions are essentially model independent. The spectral index for the scalar perturbations $n \simeq 0.92 - 0.88$, while the ratio of the tensor to the scalar quadrupole anisotropy is $(\Delta T/T)^2_T/(\Delta T/T)^2_S \approx 0.4 - 0.7$. On smaller angular scales, $\delta T/T (1^\circ ) \approx (9 - 16) \times 10^{-6}$ and $\delta T/T (2.1^\circ ) \approx (6 - 10) \times 10^{-6}$. Implications for magnetic monopoles and cosmic strings as well as the gauge hierarchy problem are pointed out.