我们用前\textit{Planck} CMB数据约束单场暴胀模型。这里使用的数据是为期9年的威尔金森微波各向异性探测器（\textit{WMAP}）数据、南极望远镜（SPT）数据和阿塔卡马宇宙学望远镜（ACT）数据。通过加入光谱指数参数的运行，我们发现$χ^2$提高了$Δχ^2=8.44$的因子，这强烈地表明了该参数从当前数据的偏好。此外，我们还发现，即使在不同的主尺度下，谱指数$α_s$的变化也不会太大，这表明功率谱的幂律展开直到一阶项都是足够精确的。此外，我们发现$r-n_{s}$的联合约束对单场暴胀模型给出了非常严格的约束，并且具有幂律势$ϕ^{p}$的模型只有当$0.9 \lesssim p \lesssim 2.1$时才能生存，因此在\textit{Planck}数据之前，已经排除了一大类暴胀模型。最后，我们使用$f_{NL}$数据来约束非平凡声速$c_s$。我们发现，目前的约束是占主导地位的功率谱约束，有一些不一致的约束，从$f_{NL}$。这就提出了\textit{WMAP}数据的功率谱和双谱之间的一致性的重要问题。
英文摘要：
We constrain models of single field inflation with the pre-\textit{Planck} CMB data. The data used here is the 9-year Wilkinson Microwave Anisotropy Probe (\textit{WMAP}) data, South Pole Telescope (SPT) data and Atacama Cosmology Telescope (ACT) data. By adding in running of spectral index parameter, we find that the $χ^2$ is improved by a factor of $Δχ^2=8.44$, which strongly indicates the preference of this parameter from current data. In addition, we find that the running of spectral index $α_s$ does not change very much even if we switch to different pivot scales, which suggests that the power law expansion of power spectrum is accurate enough till the 1st order term. Furthermore, we find that the joint constraints on $r-n_{s}$ give very tight constraints on single-field inflation models, and the models with power law potential $ϕ^{p}$ can only survive if $0.9 \lesssim p \lesssim 2.1$, so a large class of inflation models have already been ruled out before \textit{Planck} data. Finally, we use the $f_{NL}$ data to constrain the non-trivial sound speed $c_s$. We find that the current constraint is dominated by the power spectrum constraints which have some inconsistency with the constraints from $f_{NL}$. This poses important questions of consistency between power spectrum and bispectrum of \textit{WMAP} data.
First constraints on causal sources of primordial gravitational waves from BICEP/Keck, SPTpol, SPT-3G, Planck and WMAP $B$-mode data
Fermi National Accelerator Laboratory（费米国家加速器实验室）；Kavli Institute for Cosmological Physics, University of Chicago（芝加哥大学卡弗里宇宙物理研究所）；Leinweber Institute for Theoretical Physics, Stanford University（斯坦福大学莱因韦伯理论物理研究所）；School of Physics, University of Melbourne（墨尔本大学物理学院）；Department of Physics and Astronomy, Seoul National University（首尔大学物理与天文学系）；Department of Astronomy and Astrophysics, University of Chicago（芝加哥大学天文与天体物理学系）；Department of Physics and Astronomy, University of Notre Dame（圣母大学物理与天文学系）；Sorbonne Université, CNRS, UMR 7095, Institut d’Astrophysique de Paris（索邦大学，法国国家科学研究中心，UMR 7095，巴黎天体物理研究所）
The measurements of Cosmic Microwave Background anisotropies made by the Planck satellite provide extremely tight upper bounds on the total neutrino mass scale ($Σm_ν<0.26 eV$ at $95\%$ C.L.). However, as recently discussed in the literature, Planck data show anomalies that could affect this result. Here we provide new constraints on neutrino masses using the recent and complementary CMB measurements from the Atacama Cosmology Telescope DR4 and the South Polar Telescope SPT-3G experiments. We found that both the ACT-DR4 and SPT-3G data, when combined with WMAP, mildly suggest a neutrino mass w…
Updated Constraints on Omnipotent Dark Energy: A Comprehensive Analysis with CMB and BAO Data
University of Sheffield（谢菲尔德大学）；UNAM（墨西哥国立自治大学）；Universidade Federal do Rio Grande do Sul（南里奥格兰德联邦大学）；Instituto Nacional de Pesquisas Espaciais（巴西国家空间研究所）；Istanbul Technical University（伊斯坦布尔理工大学）；Jamia Millia Islamia（贾米亚米里亚伊斯兰大学）
Comments on the paper by E. Gjerlow and O. Elgaroy "Are all modes created equal ? An analysis of the WMAP 5- and 7-year data without inflationary prejudice"
The overall cosmological parameter tension between the Atacama Cosmology Telescope 2020 (ACT) and Planck 2018 data within the concordance cosmological model is quantified using the suspiciousness statistic to be 2.6$σ$. Between ACT and the South Pole Telescope (SPT) we find a tension of 2.4$σ$, and 2.8$σ$ between ACT and Planck+SPT combined. While it is unclear whether the tension is caused by statistical fluctuations, systematic effects or new physics, caution should be exercised in combining these cosmic microwave background datasets in the context of the $Λ$CDM standard model of the univers…
A promising idea to resolve the long standing Hubble tension is to postulate a new subdominant dark-energy-like component in the pre-recombination Universe which is traditionally termed as the Early Dark Energy (EDE). However, as shown in Refs. \cite{Hill:2020osr,Ivanov:2020ril} the cosmic microwave background (CMB) and large-scale structure (LSS) data impose tight constraints on this proposal. Here, we revisit these strong bounds considering the Planck CMB temperature anisotropy data at large angular scales and the SPTPol polarization and lensing measurements. As advocated in Ref. \cite{Chuda…
We revisit the degeneracy between the Hubble constant, $H_0$, and matter density, $Ω_m$, for current cosmic microwave background (CMB) observations within the standard $ΛCDM$ model. We show that Planck, Wilkinson Microwave Anisotropy Probe (WMAP), South Pole Telescope (SPT), and Atacama Cosmology Telescope Polarimeter (ACTPol) temperature power spectra produce different values of the exponent $x$ from minimizing the variance of the product $Ω_mH_0^x$. The distribution of $x$ from the different data sets does not follow the Markov Chain Monte Carlo (MCMC) best-fit values for $H_0$ or $Ω_m$. Par…
We investigate correlations induced by gravitational lensing on simulated cosmic microwave background data of experiments with an incomplete sky coverage and their effect on inferences from the South Pole Telescope data. These correlations agree well with the theoretical expectations, given by the sum of super-sample and intra-sample lensing terms, with only a typically negligible $\sim$ 5% discrepancy in the amplitude of the super-sample lensing effect. Including these effects we find that lensing constraints are in $3.0σ$ or $2.1σ$ tension between the SPT polarization measurements and Planck…
We investigate constraints on early dark energy (EDE) using ACT DR4, SPT-3G 2018, Planck polarization, and restricted Planck temperature data (at $\ell<650$), finding a $3.3σ$ preference ($Δχ^2=-16.2$ for 3 additional degrees of freedom) for EDE over $Λ$CDM. The EDE contributes a maximum fractional energy density of $f_{\rm EDE}(z_c)=0.163^{+0.047}_{-0.04}$ at a redshift $z_c=3357\pm200$ and leads to a CMB inferred value of the Hubble constant $H_0=74.2^{+1.9}_{-2.1}$ km/s/Mpc. We find that Planck and ACT DR4 data provide the majority of the improvement in $χ^2$, and that the inclusion of SPT-…
Cosmological Constraints from Sunyaev-Zel'dovich-Selected Clusters with X-ray Observations in the First 178 Square Degrees of the South Pole Telescope Survey
