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arXiv 0801.1755astro-ph
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符合问题与相互作用的全息暗能量

The Coincidence Problem and Interacting Holographic Dark Energy

Khamphee Karwan

摘要:

研究了相互作用项为$Q=3H(\lam_dρ_d + \lam_cρ_c)$的相互作用全息暗能量模型的动力学行为,其中$ρ_d$和$ρ_c$分别为暗能量和CDM的能量密度.在满足SNIa、CMB位移参数和BAO测量的观测约束条件下,如果是$\lam_c = \lam_d$或$\lam_d, \lam_c >0$,宇宙演化在未来只能到达吸引子,而$ρ_c/ρ_d$的比值目前不可能是缓慢变化的。由于即使宇宙学参数的当前值不满足观测约束,宇宙吸引子也可以在未来到达,因此在这种情况下,重合问题并没有真正得到缓解。然而,如果允许$\lam_c \neq \lam_d$和它们是负的,则比率$ρ_c/ρ_d$在当前可以是缓慢变化的,并且在当前历元附近可以达到宇宙吸引子。因此,在这种情况下,可以减轻重合问题。在这种情况下,重合问题的缓解仍然是可以实现的,当面对这个模型的SDSS数据。

英文摘要:

We study the dynamical behaviour of the interacting holographic dark energy model whose interaction term is $Q=3H(\lam_dρ_d + \lam_cρ_c)$, where $ρ_d$ and $ρ_c$ are the energy density of dark energy and CDM respectively. To satisfy the observational constraints from SNIa, CMB shift parameter and BAO measurement, if $\lam_c = \lam_d$ or $\lam_d, \lam_c >0$, the cosmic evolution will only reach the attractor in the future and the ratio $ρ_c/ρ_d$ cannot be slowly varying at present. Since the cosmic attractor can be reached in the future even when the present values of the cosmological parameters do not satisfy the observational constraints, the coincidence problem is not really alleviated in this case. However, if $\lam_c \neq \lam_d$ and they are allowed to be negative, the ratio $ρ_c/ρ_d$ can be slowly varying at present and the cosmic attractor can be reached near the present epoch. Hence, the alleviation of the coincidence problem is attainable in this case. The alleviation of coincidence problem in this case is still attainable when confronting this model to SDSS data.

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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