A predictive SO(10) model

We discuss some testable predictions of a non-sup ersymmetric SO(10) model supplemented by a Peccei-Quinn symmetry. We utilize a symmetry breaking pattern of SO(10) that yields unification of the Standard Model gauge couplings, with the unification scale also linked to inflation driven by an SO(10) singlet scalar field with a Coleman-Weinberg potential. Proton decay mediated by the superheavy gauge bosons may be observable at the proposed Hyper-Kamiokande experiment. Due to an unbroken Z2 gauge symmetry from SO(10), the model predicts the presence of a stable intermediate mass fermion which, together with the axion, provides the desired relic abundance of dark matter. The model also predicts the presence of intermediate scale topologically stable monopoles and strings that survive inflation. The monopoles may be present in the Universe at an observable level. We estimate the stochastic gravitational wave background emitted by the strings and show that it should be testable in a number of planned and proposed space and land based experiments. Finally, we show how the observed baryon asymmetry in the Universe is realized via non-thermal leptogenesis.

Automated summary

This study discusses some testable predictions of a non-supersymmetric SO(10) model supplemented by a Peccei-Quinn symmetry. The model achieves the unification of Standard Model gauge couplings through the symmetry breaking pattern of SO(10), which is also related to inflation driven by an SO(10) singlet scalar field with a Coleman-Weinberg potential. The study predicts multiple observable phenomena, including proton decay, relic abundance of dark matter, and the presence of monopoles and strings in the Universe, and estimates the stochastic gravitational wave background emitted by the strings.