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 $(Q)$ whose effective equation of state differs from that of matter, radiation or cosmological constant (Λ). 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.