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arXiv 0803.3223astro-phhep-ph
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非粒子暗物质的宇宙学约束

Cosmological constraints on unparticle dark matter

Yan Gong, Xuelei Chen

摘要:

在非粒子暗物质(非物质)模型中,非物质的状态方程由$p=ρ/(2d_U+1)$给出,其中$d_U$是比例因子。具有这种状态方程的无物质将对宇宙的膨胀历史产生重大影响。利用Ia型超新星(SNIa)、重子声学振荡(BAO)测量和宇宙微波背景(CMB)位移参数对这类非物质模型进行约束,发现如果只使用SNIa数据,约束是弱的。然而,通过BAO和CMB移位参数数据添加,可以获得强约束。对于$Λ$ UDM模型,其中非物质是唯一的暗物质,我们发现$d_U > 60$在95%C. L.相比之下,在大多数非粒子物理模型中,它被假定为$d_U<2$。对于非物质与冷暗物质共存的$Λ$ CUDM模型,我们发现在$d_U<10$模型中,非物质最多只能占宇宙总密度的百分之几,因此它不可能是暗物质的主要成分。

英文摘要:

In unparticle dark matter (unmatter) models the equation of state of the unmatter is given by $p=ρ/(2d_U+1)$, where $d_U$ is the scaling factor. Unmatter with such equations of state would have a significant impact on the expansion history of the universe. Using type Ia supernovae (SNIa), the baryon acoustic oscillation (BAO) measurements and the shift parameter of the cosmic microwave background (CMB) to place constraints on such unmatter models we find that if only the SNIa data is used the constraints are weak. However, with the BAO and CMB shift parameter data added strong constraints can be obtained. For the $Λ$UDM model, in which unmatter is the sole dark matter, we find that $d_U > 60$ at 95% C.L. For comparison, in most unparticle physics models it is assumed $d_U<2$. For the $Λ$CUDM model, in which unmatter co-exists with cold dark matter, we found that the unmatter can at most make up a few percent of the total cosmic density if $d_U<10$, thus it can not be the major component of dark matter.

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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