| Abstract: |
An almost scale-invariant, Gaussian and parity-conserving stochastic gravitational wave background is produced, according to the simplest inflationary scenario, by quantum vacuum fluctuations in the early Universe. This simple picture appears to be the one favoured by current cosmological datasets. However, upcoming observational campaigns - such as the LiteBIRD satellite - could subvert this scenario by detecting deviations from scale-invariance, Gaussianity and/or parity conservation in the primordial gravitational wave background, which could be produced for instance by additional fields present during inflation. Specifically, we will consider gravitational waves production from gauge fields sources and discuss the current state and the future developments of observations from both CMB and direct detection experiments. |
