Speaker
Description
The cold, collisionless dark matter (DM) postulated in the $\Lambda CDM$ model leads to several small scale anomalies such as the cusp-core problem, the missing satellites problem and the too big to fail problem. Self-interacting dark matter (SIDM), a promising alternative type of dark matter, not only alleviates the small scale anomalies, but also matches with highly accurate large scale predictions of the $\Lambda CDM$ model. However, in the standard cosmology, the thermal relic of SIDM is below the observed DM relic density due to large annihilation cross-section. Therefore, we make an attempt to realise the correct thermal relic of SIDM by assuming a non-standard cosmological history. This is achieved by introducing an additional scalar field to the standard scenario. The SIDM is assumed to be a Dirac fermion, while the mediator needed to facilitate the self-interaction can be either a light scalar or boson. We study the phenomenological consequences in the SIDM sector in non-standard cosmology, including relic density, direct and indirect searches. We find out the viable parameter space for the model after confronting with relevant phenomenological and experimental constraints.
