Gravitational Waves Produced during the Inflationary Epoch

A detailed and comprehensive description of the mathematical tools needed to understand the generation of inflationary gravitational waves. The inflationary gravitational wave power spectrum is successfully reproduced based on a quantum field theory in an expanding universe. The power spectrum is computed using a simple cosmological model of the evolution of the early universe, in which a sequence of Bogoliubov transformations result in the inflationary gravitational waves. Furthermore, the recent efforts into indirectly and directly detecting inflationary gravitational waves and the significance of a detection is discussed.