Quantifying $S_8$ tension and evidence for interacting dark energy from redshift-space distortion measurements
| Autor: | Sabogal, Miguel A., Silva, Emanuelly, Nunes, Rafael C., Kumar, Suresh, Di Valentino, Eleonora, Giarè, William |
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| Rok vydání: | 2024 |
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| Druh dokumentu: | Working Paper |
| Popis: | In recent years, Cosmic Microwave Background (CMB) observations, Weak Lensing surveys, and $f(z)\sigma_8(z)$ measurements from Redshift-Space Distortions (RSD) have revealed a significant ($\sim$3$-$5$\sigma$) discrepancy in the inferred value of the matter clustering parameter $S_8$. In this work, we investigate the implications of RSD for a cosmological framework postulating an interaction between Dark Energy (DE) and Dark Matter (DM). We explore scenarios where DM can transfer energy-momentum to DE or vice versa. The energy-momentum flow is characterized by the strength and the sign of the coupling parameter $\xi$. Our baseline analysis combines RSD measurements with the latest data from Baryon Acoustic Oscillations (BAO) observed by DESI, Type Ia Supernovae from the PantheonPlus sample, and CMB data from Planck. We demonstrate that RSD measurements provide significant additional information. When energy-momentum flows from DM to DE (i.e., $\xi < 0$), these measurements set stringent new bounds on the interaction strength. Conversely, when energy-momentum flows from DE to DM ($\xi > 0$), they favor interactions at more than the $2\sigma$ confidence level. Models with $\xi > 0$ can effectively resolve the tension in $S_8$, presenting them as compelling alternatives. Comment: 13 pages, 6 figures. Comments welcome and appreciated |
| Databáze: | arXiv |
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