http://arxiv.org/abs/2301.03939
Considering possible solutions to the $S_8$ tension between the Planck cosmic microwave background (CMB) measurement and low-redshift probes, we extended the standard $\Lambda$CDM cosmological model by including decay of dark matter (DDM). We first tested the DDM model in which dark matter decays into a form of non-interacting dark radiation. Under this DDM model, we investigated the DDM’s impacts on the Sunyaev Zel’dovich effect by varying the decay lifetime, $\Gamma^{-1}$, including the background evolution in cosmology and non-linear prescription in the halo mass function. We performed a cosmological analysis under the assumption of this extended cosmological model by combining the latest high-redshift Planck CMB measurement and low-redshift SZ measurement. Our result shows a preference for $\Gamma^{-1} \sim 200$ Gyr with a lower bound on the decay lifetime of $\sim$ 77 Gyr at 95\% confidence level. However, the CMB data do not prefer this model, and the $S_8$ tension still remains. Additionally, we tested the other DDM model in which dark matter decays into warm dark matter and dark radiation. This model supports $\Gamma^{-1} \sim 204$ Gyr to resolve the $S_8$ tension with a lower bound on the decay lifetime of $\sim$ 47 Gyr at 95\% confidence level.
H. Tanimura, M. Douspis, N. Aghanim, et. al.
Wed, 11 Jan 23
35/80
Comments: 8 pages, 5 figures
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