Relic abundance of dark matter with coannihilation in non-standard cosmological scenarios

We investigate the relic abundance of dark matter from coannihilation in non-standard cosmological scenarios. We explore the effect of coannihilation on the relic density of dark matter and freeze out temperature in quintessence model with kination phase and brane world cosmological scenarios. Since the Hubble expansion rate is enhanced in quintessence and brane world cosmological models, it causes the larger relic density compared to that in the standard one. On the other hand, the relic density of dark matter is decreased due to the coannihilation in the standard cosmological scenario. After including coannihilation in quintessence or brane world cosmological scenarios, we find the decrease of the relic density of dark matter is slightly slower than that in the standard cosmological scenario.