arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 1702.01291astro-ph.COgr-qc
收藏

未来星系巡天最终可探测的尺度相关扰动及其对宇宙学模型选择的贡献

Scale-dependent perturbations finally detectable by future galaxy surveys and their contribution to cosmological model selection

Tomasz Denkiewicz, Vincenzo Salzano

摘要:

通过目前的几何和动力学观测数据,这是非常困难的,从统计的角度来看,建立一个明确的偏好,在绝大多数的动力学暗能量和/或修改的重力理论的替代方案,相对于$Λ$ CDM方案的建议模型。另一方面,在比当前哈勃尺度小得多的尺度上,即使在$Λ$ CDM模型的背景下,不同扰动模式的物质扰动增长也可能存在可检测到的差异。在这里,我们分析的背景下,$Λ$ CDM和一些动力学暗能量模型的暗物质扰动的演变涉及未来的宇宙学奇异性,如突然的未来奇异性和有限的标度因子奇异性。我们采用牛顿规范制定的增长函数的微扰方程的推导,我们放弃了亚哈勃近似和缓慢变化的潜在的假设。我们将Fisher矩阵方法应用于三个未来计划的星系调查,例如,DESI、Euclid和WFirst-2.4。通过手头上提到的调查,只有通过动态探针,我们将实现多个目标:$1.$确定$fσ_{8}$的准确性的提高将使区分$Λ$ CDM和替代的暗能量模型成为可能,即使在尺度独立方法中也是如此; $2.$最终将有可能检验尺度独立性的良好性,并且还可以量化对扰动增长的尺度相关方法的必要性,特别是使用包含具有尺度$k<0.005\,h$ Mpc $^{-1}$ ; $3.$的红移仓的测量,尺度依赖性本身通常可以增加更多的鉴别能力,但是需要进一步的高级测量。

英文摘要:

By means of the present geometrical and dynamical observational data, it is very hard to establish, from a statistical perspective, a clear preference among the vast majority of the proposed models for the dynamical dark energy and/or modified gravity theories alternative with respect to the $Λ$CDM scenario. On the other hand, on scales much smaller than present Hubble scale, there are possibly detectable differences in the growth of the matter perturbations for different modes of the perturbations, even in the context of the $Λ$CDM model. Here, we analyze the evolution of the dark matter perturbations in the context of $Λ$CDM and some dynamical dark energy models involving future cosmological singularities, such as the sudden future singularity and the finite scale factor singularity. We employ the Newtonian gauge formulation for the derivation of the perturbation equations for the growth function, and we abandon both the sub-Hubble approximation and the slowly varying potential assumption. We apply the Fisher Matrix approach to three future planned galaxy surveys e.g., DESI, Euclid, and WFirst-2.4. With the mentioned surveys on hand, only with the dynamical probes, we will achieve multiple goals: $1.$ the improvement in the accuracy of the determination of the $fσ_{8}$ will give the possibility to discriminate between the $Λ$CDM and the alternative dark energy models even in the scale-independent approach; $2.$ it will be possible to test the goodness of the scale-independence finally, and also to quantify the necessity of a scale dependent approach to the growth of the perturbations, in particular using surveys which encompass redshift bins with scales $k<0.005\,h$ Mpc$^{-1}$; $3.$ the scale-dependence itself might add much more discriminating power in general, but further advanced surveys will be needed.

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。

↑