Power Spectra Based Planck Constraints on Compensated Isocurvature, and Forecasts for LiteBIRD and CORE Space Missions
Power Spectra Based Planck Constraints on Compensated Isocurvature, and Forecasts for LiteBIRD and CORE Space Missions
复制标题
基于功率谱的普朗克补偿等曲率约束以及 LiteBIRD 和 CORE 空间任务的预测
DOI：
--
复制
发表时间：
2017
期刊：
影响因子：
--
通讯作者：
J. Valiviita
中科院分区：
文献类型：
--
作者：
J. Valiviita
补偿等温扰动(CIP)，其中重子扰动和冷暗物质扰动相互抵消，不会引起总物质等温扰动。因此，在重子密度对比度的线性数量级上，CMB功率谱不能探测到CIP。在二阶，CIP以类似于透镜的方式平滑功率谱，导致CIP方差$\Delta^2_{rms}=$与透镜参数$A_L$之间的简并。我们发现，CMB透镜数据打破了这种简并。对LCDM+CIP(+$A_L$)模型的嵌套采样，普朗克2015年的温度、偏振和透镜数据给出了68%CL时的$\Delta^2_{rms}=0.0069\pm0.0030$。非零值优先于2.3$\sigma$。与绝热LCDM模型相比，最优拟合度比绝热LCDM模型提高3.6倍。相反，尽管温度数据支持$A_L=1.22$，但允许$A_L\NE1$并不能改善接头拟合度，因为透镜数据不支持$A_L\NE1$。事实上，CIP提供了一个罕见的简单模型的例子，它可以通过同时很好地拟合高多极温度和透镜数据以及偏振数据来减少普朗克透镜异常。最后，我们得出了对未来卫星任务的预测(向日本宇宙航空研究开发机构提出的LiteBIRD建议和对欧空局M5呼吁的核心建议的探索宇宙起源)。由于其较低的角分辨率，LiteBIRD不能改善对CIP或$A_L的约束，但CORE-M5接近宇宙方差极限，并将CIP约束提高到68%(95%)CL处的$\Delta^2_{rms}<；0.0006\(0.0014)$，这比目前基于三谱的上限高9倍，比模拟普朗克数据的高6倍。此外，CORE-M5将精细区分CIP和$A_L$。无论是否允许CIP，透镜参数的不确定度将为$\sigma(A_L)=0.012$。
Compensated isocurvature perturbations (CIP), where the baryon and cold dark matter perturbations cancel, do not cause total matter isocurvature perturbation. Consequently, at the linear order in the baryon density contrast $\Delta$, CIP is not detectable by the CMB power spectra. At the second order CIP smoothes the power spectra in a similar manner as lensing, causing a degeneracy between the CIP variance $\Delta^2_{rms}= $ and lensing parameter $A_L$. We show that the CMB lensing data breaks this degeneracy. Nested sampling of the LCDM+CIP(+$A_L$) model, the Planck 2015 temperature, polarization, and lensing data give $\Delta^2_{rms}=0.0069\pm0.0030$ at 68% CL. A non-zero value is favored at 2.3$\sigma$. CIP with $\Delta^2_{rms}=0.007$ improves the bestfit $\chi^2$ by 3.6 compared to the adiabatic LCDM model. In contrast, although the temperature data favor $A_L=1.22$, allowing $A_L\ne1$ does not improve the joint fit, since the lensing data disfavor $A_L\ne1$. Indeed, CIP provides a rare example of a simple model, which can reduce the Planck lensing anomaly by fitting well simultaneously the high multipole temperature and lensing data, as well as the polarization data. Finally, we derive forecasts for future satellite missions (LiteBIRD proposal to JAXA and Exploring Cosmic Origins with CORE proposal to ESA's M5 call). Due to its coarse angular resolution, LiteBIRD is not able to improve the constraints on CIP or $A_L$, but CORE-M5 approaches the cosmic variance limit and improves the CIP constraint to $\Delta^2_{rms}<0.0006\ (0.0014)$ at 68% (95%) CL, which is 9 times better than the current trispectrum based upper bound and 6 times better than obtained from the simulated Planck data. In addition, CORE-M5 will exquisitely distinguish between CIP and $A_L$. No matter whether CIP is allowed for or not, the uncertainty of the lensing parameter will be $\sigma(A_L)=0.012$.
重子声振荡总质量与发光物质的大规模分布：斯隆数字巡天 III 重子振荡光谱巡天数据第 10 版中的首次搜索。
影响因子：
8.6
作者：
Soumagnac MT
通讯作者：
Soumagnac MT
DOI：
10.17863/cam.43425
发表时间：
2016
期刊：
--
影响因子：
--
作者：
Aghanim N
通讯作者：
Aghanim N