Observational signatures of dark energy produced in an ancestor vacuum: forecast for galaxy surveys
Observational signatures of dark energy produced in an ancestor vacuum: forecast for galaxy surveys
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DOI：
10.1088/1475-7516/2019/05/055
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发表时间：
2018-07
影响因子：
6.4
通讯作者：
Daisuke Yamauchi;H. Aoki;S. Iso;Da-Shin Lee;Y. Sekino;Chen-Pin Yeh
中科院分区：
文献类型：
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作者：
Daisuke Yamauchi;H. Aoki;S. Iso;Da-Shin Lee;Y. Sekino;Chen-Pin Yeh
我们研究了[1]中提出的暗能量模型的观测结果。我们假设我们的宇宙是由气泡成核形成的，并考虑超轻标量场的量子涨落。在祖先真空（气泡形成的德西特空间）中产生的波动的残余效应被解释为暗能量。其状态方程参数wDE(z)有一个特征形式，在未来接近-1，但在过去接近-1/3。我们模型的一个新颖特征是，暗能量有效地增加了哈勃参数演化中负空间曲率的大小，尽管它不会改变角直径距离的定义。我们通过Fisher分析来预测未来平方公里阵列和欧几里得星系巡天对我们模型的约束，并指出我们的模型可以与通常的ΛCDM模型区分开来，合理选择参数。由于暗能量和空间曲率之间的简并性，单独通过星系巡天可能很难完全确定模型参数，但结合其他独立观测，例如CMB，将大大提高确定模型参数的机会。
We study observational consequences of the model for dark energy proposed in [1]. We assume our universe has been created by bubble nucleation, and consider quantum fluctuations of an ultralight scalar field. Residual effects of fluctuations generated in an ancestor vacuum (de Sitter space in which the bubble was formed) is interpreted as dark energy. Its equation of state parameter wDE(z) has a characteristic form, approaching −1 in the future, but −1/3 in the past. A novel feature of our model is that dark energy effectively increases the magnitude of the negative spatial curvature in the evolution of the Hubble parameter, though it does not alter the definition of the angular diameter distance. We perform Fisher analysis to forecast the constraints for our model from future galaxy surveys by Square Kilometre Array and Euclid, and point out that our model can be distinguished from the usual ΛCDM model for reasonable choices of the parameters. Due to degeneracy between dark energy and the spatial curvature, it might be difficult to fully determine the model parameters by galaxy surveys alone, but combination with other independent observations, such as CMB, will greatly improve the chance of determining them.