Violation of the Weak Energy Condition by the Inflationary Yang-Mills Condensate

Recent cosmic microwave background data favours a blue-tilted primeval perturbation spectrum with an index n > 1, which implies that the equation of state of dominant matter should be such that ρ+p < 0 during the inflationary expansion of the early universe. We study the quantum Yang-Mills condensate inflationary model and find that this requirement can be satisfied by the effective quantum Yang-Mills condensate naturally in the states with the negative dielectric constant.