[论文解读] Interacting Dark Energy after DESI Baryon Acoustic Oscillation measurements

William Giarè, Miguel A. Sabogal+2 more|arXiv (Cornell University)|Apr 23, 2024

Cosmology and Gravitation Theories被引用 11

一句话总结

使用 Planck-2018 和 DESI BAO 数据，本文在相互作用暗能量模型中发现对非零暗物质-暗能量耦合（xi < 0）的偏好，得到 H0 约为 71.4 km/s/Mpc，并有助于缓解哈勃常数张力；结合额外的 SN 和宇钟数据显示，结果仍然有利。

ABSTRACT

We investigate the implications of the Baryon Acoustic Oscillations measurement released by the Dark Energy Spectroscopic Instrument (DESI) for Interacting Dark Energy (IDE) models characterized by an energy-momentum flow from Dark Matter to Dark Energy. By combining Planck-2018 and DESI data, we observe a preference for interactions, leading to a non-vanishing interaction rate $ξ=-0.32^{+0.18}_{-0.14}$, which results in a present-day expansion rate $H_0=70.8^{+1.4}_{-1.7}$ km/s/Mpc, reducing the tension with the value provided by the SH0ES collaboration to less than $\sim 1.3 σ$. The preference for interactions remains robust when including measurements of the expansion rate $H(z)$ obtained from the relative ages of massive, early-time, and passively-evolving galaxies, as well as when considering distance moduli measurements from Type-Ia Supernovae sourced from the Pantheon-plus catalog using the SH0ES Cepheid host distances as calibrators. Overall, the IDE framework provides an equally good, or better, explanation of both high- and low-redshift background observations compared to $Λ$CDM, while also yielding higher $H_0$ values that align more closely with the local distance ladder estimates. However, a limitation of the IDE model is that it predicts lower $Ω_{m}$ and higher $σ_{8}$ values, which may not be fully consistent with large-scale structure data at the perturbation level.

研究动机与目标

• 推动在 ΛCDM 之外的晚期宇宙新物理以解决哈勃张力的探索。
• 评估 DESI BAO 数据如何约束具有 DM 到 DE 能量转移的相互作用式暗能量模型。
• 量化 IDE 在与 Planck-2018 及其他低-和高红移探测数据组合时对 H0 与 Omega_m 的影响。

提出的方法

• 采用一个 IDE 框架，其 DM 向 DE 的能动量转移为 Q = H xi rho_DE，DE 的方程状态近似为宇宙常数，即 w ≈ -1。
• 通过设定 w = -1 + epsilon 且 epsilon ≈ 0（epsilon → 0）来调和早时期摄动不稳定性。
• 修改波动方程数值代码 CLASS 以包含 IDE，并使用 COBAYA 进行 MCMC 采样分析。
• 使用 Planck-2018 CMB 似然和 DESI BAO 测量（D_M/r_d、D_H/r_d、D_V/r_d）及其相关性。
• 结合带有 SH0ES Cepheid 标定的 SN Pantheon-plus 数据和 CC H(z) 测量，以检验 IDE 约束的鲁棒性。

实验结果

研究问题

• RQ1 DESI BAO 数据是否偏好 IDE 模型中非零的 DM 向 DE 能量转移参数 xi？
• RQ2 在 IDE 下，与 LCDM 相比，Planck-2018+DESI 对 H0 和 Omega_m 的影响如何？
• RQ3 当与 Planck+DESI 组合时，SN（Pantheon-plus 配合 SH0ES 标定）和宇钟衡量对 IDE 的偏好是否仍然存在？
• RQ4 在不同 redshift 下，IDE 对 BAO 距离量的预测与 LCDM 相比如何？
• RQ5 在包含 DESI 信息时，高红移和低红移数据是否联合偏向 IDE 而非 LCDM？

主要发现

• Planck-2018+DESI yields xi = -0.38^{+0.18}_{-0.16}, indicating a preference for nonzero DM-to-DE transfer at >95% CL.
• The joint Planck+DESI analysis gives H0 = 71.4 ± 1.5 km/s/Mpc, in agreement with SH0ES.
• Adding CC or SN data maintains xi ≠ 0 at >95% CL and keeps higher H0 values than LCDM.
• For all datasets, IDE yields a lower (better) chi-squared than LCDM (Δχ^2 negative).
• Bayesian evidence (ln B_ij) is inconclusive, with IDE and LCDM fitting current data plausibly on equal footing despite improvements in χ^2.]
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• Planck-2018+DESI 得到 xi = -0.38^{+0.18}_{-0.16}，表明在 >95% 可信区间内偏好非零的 DM 向 DE 转移。
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