Primordial monopoles and strings, inflation, and gravity waves
Joydeep Chakrabortty, G. Lazarides, Rinku Maji, Qaisar Shafi
Abstract
A bstract 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 ∼ 10 13 − 10 14 GeV and flux ≲ 2 . 8 × 10 − 16 cm − 2 s − 1 sr − 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.