Abstract Details
| Name: Atanu Guha Affiliation: BITS Pilani, Goa Campus Conference ID: ASI2019_523 Title : Constraints on light Dark Matter fermions from relic density consideration, SN1987A cooling and the role of Tsallis statistics Authors and Co-Authors : Atanu Guha, Bhupal Dev, Prasanta Kumar Das Abstract Type : Oral Abstract Category : General Relativity and Cosmology Abstract : Dark Matter(DM) fermions pair produced due to the annihilation of the electron-positron pair inside supernova SN1987A core, contribute to its energy loss rate. Similar type of DM fermions (having similar interaction to the electron-positron pair) could have contributed to the relic density of the Universe as well. Working with an effective leptophilic coupling (coupling between the electron-positron pair and the DM fermions due to a four-fermi interaction) we obtain an upper bound on the effective scale Λ using the relic density of cold non-baryonic matter Ωh^2 = 0.1186±0.0020 and a lower bound using Raffelt’s criterion on the emissivity ̇≤ 10^19 erg g^{−1} s^{−1} for any new physics channel. A consistent lower bound has also been obtained using the optical depth criterion where we considered that the DM fermions are freely streaming out of the outer 10% of the SN1987A core without being trapped due to the scatterings. We worked in a scenario where the temperature fluctuation and other non-equilibrium conditions which may arise inside supernova core (because the explosion is abrupt and happens only within 10 seconds), has been taken care of using a non-equilibrium statistics, namely Tsallis statistics. Tsallis statistics can play a vital role during the early era of the Universe as well to take care of the non-equilibrium conditions at early stages. The effective degrees of freedom of the early Universe gets affected due to non-equilibrium conditions, which in turn affects the bound obtained on the energy scale of the effective theory from the relic density of non-baryonic matter. All the limits mentioned above has been compared with several direct detection bounds like XENON10, SuperCDMS and LBECA bounds. |