Gravitational dark matter: free streaming and phase space distribution

Understand

Gravitational dark matter (DM) is the simplest possible scenario that has recently gained interest in the early universe cosmology.

• In this scenario, DM is assumed to be produced from the decaying inflaton through the gravitational interaction during reheating.
• Gravitational production from the radiation bath will be ignored as our analysis shows it to be suppressed for a wide range of reheating temperatures.
• Ignoring any other internal parameters except the DM mass and spin, a particular inflation model such as $\alpha$-attractor, with a specific scalar spectral index $(n_s)$ has been shown to uniquely fix the dark matter mass.