Quantum Gauge Fields in Cosmology: Cosmic Inflation and Gravitational Waves

Sammanfattning: In this thesis, the consequences of introducing Yang-Mills fields into cosmology are investigated. This is done by the effective action approach, in which the coupling constant is allowed to depend on the quantum fields. The equation of state and scale factor are then found for the flat universe filled with either chromoelectric or chromomagnetic fields. From this, we draw conclusions about the history and fate of the universe. Then, the effect of such cosmological Yang-Mills fields on the amplitude and amplification of primordial gravitational waves are discussed.