Primordial monopoles and strings, inflation, and gravity waves

Abstract

Abstract We consider magnetic monopoles and strings that appear in non-supersymmetric SO(10) and E 6 grand unified models paying attention to gauge coupling unification and proton decay in a variety of symmetry breaking schemes. The dimensionless string tension parameter Gμ spans the range 10 −6 − 10 −30, where G is Newton’s constant and μ is the string tension. We show how intermediate scale monopoles with mass ∼ 1013 − 1014 GeV and flux ≲ 2.8 × 10 −16 cm −2s −1sr −1, and cosmic strings with Gμ ∼ 10 −11 − 10 −10 survive inflation and are present in the universe at an observable level. We estimate the gravity wave spectrum emitted from cosmic strings taking into account inflation driven by a Coleman-Weinberg potential. The tensor-to-scalar ratio r lies between 0.06 and 0.003 depending on the details of the inflationary scenario.

Keywords

• GUT
• Cosmology of Theories beyond the SM
• Gauge Symmetry
• Spontaneous Symmetry Breaking