Imprint of gravitational waves in models dominated by a dynamical cosmic scalar field

An alternative to the standard cold dark matter model has been recently proposed in which a significant fraction of the energy density of the universe is due to a dynamical scalar field $\mathrm{}\left(Q\right)\mathrm{}$ whose effective equation of state differs from that of matter, radiation or cosmological constant $\left(\Lambda \right).\mathrm{}$ In this paper, we determine how the $Q$ component modifies the primordial inflation gravitational wave (tensor metric) contribution to the cosmic microwave background anisotropy and, thereby, one of the key tests of inflation.