Graviton mass might reduce tension between early and late time cosmological data
Graviton mass might reduce tension between early and late time cosmological data
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引力子质量可能会减少早期和晚期宇宙学数据之间的紧张关系
DOI：
10.1103/physrevlett.118.091104
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发表时间：
2017
影响因子：
8.6
通讯作者：
A. De Felice and S. Mukohyama
中科院分区：
文献类型：
--
作者：
Y.Namekawa;渡邉和宏，藤井宏次;A. De Felice and S. Mukohyama
标准的冷暗物质模型与宇宙学常数（-CDM）预测的增长的结构往往是高于红移空间畸变（RSD）的测量值，如果宇宙学参数是固定的宇宙微波背景数据。在这封信中，我们指出，如果我们假设引力子有一个小的但非零的质量，这个矛盾就可以解决或理解。在最小质量引力理论（MTMG）的背景下，由于只有在目前的宇宙尺度下才能测量到的红外洛伦兹破坏，引力子获得了质量，而不会被不必要的额外自由度所困扰。虽然MTMG中所谓的宇宙学解的自加速分支与广义相对论（GR）中的背景以及标量和矢量型线性微扰具有相同的现象学，但可以选择另一个分支，使得背景与GR中的背景相同，但物质微扰的演化被引力子质量修改。在研究这种修改后的动力学对上述RSD测量的拟合时，我们发现该模型比MTMG的可能性小2个数量级。借助积分的萨克斯-沃尔夫效应和大尺度结构之间的互相关，数据还确定了引力子质量的平方，这与最近LIGO观测的最新边界一致。
The standard cold dark matter model with a cosmological constant (-CDM) predicts a growth of structures which tends to be higher than the values of redshift space distortion (RSD) measurements if the cosmological parameters are fixed by the cosmic microwave background data. In this Letter, we point out that this discrepancy can be resolved or understood if we assume that the graviton has a small but nonzero mass. In the context of the minimal theory of massive gravity (MTMG), due to infrared Lorentz violations measurable only at present cosmological scales, the graviton acquires a mass without being haunted by unwanted extra degrees of freedom. While the so-called self-accelerating branch of cosmological solutions in the MTMG has the same phenomenology for the background as well as the scalar- and vector-type linear perturbations as thein general relativity (GR), it is possible to choose another branch so that the background is the same as that in GR, but the evolution of matter perturbations gets modified by the graviton mass. In studying the fit of such modified dynamics to the above-mentioned RSD measurements, we find that themodel is less probable than the MTMG by 2 orders of magnitude. With the help of the cross-correlation between the integrated Sachs-Wolfe effect and the large-scale structure, the data also pin down the graviton mass squared around, which is consistent with the latest boundset by the recent LIGO observation.