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arXiv 1303.0684astro-ph.COgr-qc
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相互作用暗能量模型中的稳定大尺度微扰

Stable Large-Scale Perturbations in Interacting Dark-Energy Model

Cheng-Yi Sun, Rui-Hong Yue

摘要:

发现在暗扇形相互作用$Q$正比于冷暗物质能量密度(CDM)$ρ_m$和暗能量状态参数$w_d$为常数的模型中,超哈勃尺度上的密度扰动演化是不稳定的.为了避免不稳定性,本文提出了一种新的能量-动量传递的协变模型。然后,我们证明了在我们的模型中,在只被DE和CDM填充的宇宙中,曲率扰动的大尺度不稳定性是可以避免的。此外,通过引入辐射和重子的附加分量,我们计算了辐射时代的主要非绝热模,发现这些模在单位数量级上以指数的幂律增长。

英文摘要:

It is found that the evolutions of density perturbations on the super-Hubble scales are unstable in the model with dark-sector interaction $Q$ proportional to the energy density of cold dark matter (CDM) $ρ_m$ and constant equation of state parameter of dark energy $w_d$. In this paper, to avoid the instabilities, we suggest a new covariant model for the energy-momentum transfer between DE and CDM. Then we show that the the large-scale instabilities of curvature perturbations can be avoided in our model in the universe filled only by DE and CDM. Furthermore, by including the additional components of radiation and baryons, we calculate the dominant non-adiabatic modes in the radiation era and find that the modes grow in the power law with exponent at the order of unit.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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