Probing the early universe with future GW observatories

Understand

One of the fundamental characteristics of slow roll inflation is its generation of tensor perturbations, which manifest as stochastic gravitational waves (GWs).

• Slow roll inflation results in a nearly scale-invariant GW spectrum that maintains its scale invariance as it transitions into the radiation-dominated era.
• However, introducing an intermediate reheating phase can modify the spectral tilt, depending on the equation of state governing that particular epoch.
• These GWs, especially on smaller scales, are anticipated to be observable by forthcoming GW detectors.