Monopoles, strings and gravitational waves in non-minimal inflation

Abstract

Abstract We discuss how in SO(10) grand unification an observable number density of topologically stable intermediate mass (∼ 1014 GeV) monopoles survive inflation driven by a Coleman-Weinberg potential and non-minimal coupling of the inflaton field to gravity. The scalar spectral index ns is in excellent agreement with the current observations, and the tensor to scalar ratio r ≳ 0.003. The model also predicts the presence of intermediate scale topologically stable cosmic strings, and their gravitational wave spectrum reflects the amount of cosmic inflation experienced by the associated symmetry breaking. The discovery of these primordial monopoles and the stochastic gravitational wave background from the strings would provide important new insights regarding the symmetry breaking patterns in the early universe.