我们探讨了普朗克2015年温度和偏振数据中的特征、宇宙学参数的变化以及暴胀特征之间的关系。在低多极$\ell$温度数据中的残差，这是导致幂律$Λ$ CDM模型中$\ell<1000$的高$H_0\approx 70$ km s $^{-1}$ Mpc $^{-1}$和低$σ_8Ω_m^{1/2}$值的原因，更好地拟合膨胀特征，其中$1.9σ$偏好倾斜的运行或更强的$99\%$ CL局部显著性偏好在广义$k=0.004$ Mpc $^{-1}$附近功率急剧下降。低速滚转和较低$H_0\approx 67$ km s $^{-1}$ Mpc $^{-1}$。在$\ell>1000$处的相同同相声学残差驱动全局$H_0$约束并表现为透镜异常，这也有利于允许甚至更低的$H_0$的运行参数，但一旦考虑透镜重建就不行。偏振光谱本质上对这些参数变化非常敏感，在普朗克2015 TE数据中更是如此，因为在$\ell \approx 165$处存在离群值，这使最佳拟合的$H_0$ $Λ$ CDM解的不利性超过$2σ$，并且几乎在$3σ$处存在高$H_0$值。目前的极化数据也稍微提高了大规模功率的急剧抑制的意义，但在未来的宇宙方差有限的$E$模式测量留下了很大的改进空间。
英文摘要：
We explore the relationship between features in the Planck 2015 temperature and polarization data, shifts in the cosmological parameters, and features from inflation. Residuals in the temperature data at low multipole $\ell$, which are responsible for the high $H_0\approx 70$ km s$^{-1}$Mpc$^{-1}$ and low $σ_8Ω_m^{1/2}$ values from $\ell<1000$ in power-law $Λ$CDM models, are better fit to inflationary features with a $1.9σ$ preference for running of the running of the tilt or a stronger $99\%$ CL local significance preference for a sharp drop in power around $k=0.004$ Mpc$^{-1}$ in generalized slow roll and a lower $H_0\approx 67$ km s$^{-1}$Mpc$^{-1}$. The same in-phase acoustic residuals at $\ell>1000$ that drive the global $H_0$ constraints and appear as a lensing anomaly also favor running parameters which allow even lower $H_0$, but not once lensing reconstruction is considered. Polarization spectra are intrinsically highly sensitive to these parameter shifts, and even more so in the Planck 2015 TE data due to an outlier at $\ell \approx 165$, which disfavors the best fit $H_0$ $Λ$CDM solution by more than $2σ$, and high $H_0$ value at almost $3σ$. Current polarization data also slightly enhance the significance of a sharp suppression of large-scale power but leave room for large improvements in the future with cosmic variance limited $E$-mode measurements.
Updating constraints on inflationary features in the primordial power spectrum with the Planck data
根据普朗克卫星最近对宇宙微波背景各向异性的测量，我们提出了对原始暴胀密度扰动功率谱中可能特征的新约束。我们发现，普朗克数据暗示了在两个不同的角标度范围内存在特征，对应于10< l <60和150< l < 300的多极子，在这两种情况下，相对于无特征的“香草”LCDM模型，最佳拟合的χ 2值都在9左右。
We study the implications of the recently proposed Trans-Planckian Censorship Conjecture (TCC) for early universe cosmology and in particular inflationary cosmology. The TCC leads to the conclusion that if we want inflationary cosmology to provide a successful scenario for cosmological structure formation, the energy scale of inflation has to be lower than $10^9$ GeV. Demanding the correct amplitude of the cosmological perturbations then forces the generalized slow-roll parameter $ε$ of the model to be very small ($<10^{-31}$). This leads to the prediction of a negligible amplitude of primordi…
We study the constraint on the inflationary energy scale from the recently proposed Trans-Planckian Censorship Conjecture (TCC). We find a universal upper bound on the inflationary Hubble expansion rate $H_\text{inf}$ which is solely determined by the reheating temperature $T_\text{rh}$: $H_\text{inf}/M_\text{Pl}\lesssim T_0/T_\text{rh}$, where $T_0$ is the photon temperature today. The upper limit can be saturated by a post-inflationary oscillatory stage with the critical equation-of-state parameter $w\approx-1/3$, or by an inflation model with multiple stages. In the lowest reheating tempera…
We study the dynamics of two concrete inflationary models, namely Spontaneous Symmetry Breaking Inflation as well as Loop Inflation. We constrain the parameters for which a viable inflationary Universe emerges using the latest PLANCK results of last year, and we give predictions for the duration of reheating as well as for the reheating temperature after inflation. Our numerical results show that baryogenesis via leptogenesis may be realized within the inflationary models considered in this work.
We present three non-parametric Bayesian primordial reconstructions using Planck 2018 polarization data: linear spline primordial power spectrum reconstructions, cubic spline inflationary potential reconstructions and sharp-featured primordial power spectrum reconstructions. All three methods conditionally show hints of an oscillatory feature in the primordial power spectrum in the multipole range $\ell\sim20$ to $\ell\sim50$, which is to some extent preserved upon marginalization. We find no evidence for deviations from a pure power law across a broad observable window ($50\lesssim\ell\lesssi…
Bayesian analysis of inflationary features in Planck and SDSS data
我们进行贝叶斯分析，研究标量扰动的原始暴胀功率谱中可能的功能。特别地，我们分析了在宇宙微波背景（CMB）的各向异性温度功率谱和物质功率谱P（k）中检测这些原始特征的印记的可能性。我们使用普朗克合作组织提供的最新CMB数据和斯隆数字巡天第11次数据发布的P（k）测量。我们把我们的分析集中在一类潜在的功能是本地化在不同的间隔角标度，对应的多极范围10 < l < 60（Oscill-1）和150 < l < 300（Oscill-2）。我们的研究结果表明，一个步骤电位（Oscill-1）提供了一个更好的适合CMB的数据比无特征的LCDM的情况下，与温和的贝叶斯证据有利于前者。将P（k）数据添加到分析中，削弱了Oscill-1势相对于标准模型的证据，并加强了后一种情况相对于Oscill-2模型的证据。
If the inflationary phase lasted longer than the minimal period, the length scales observed today originate from modes that were smaller than the Planck length during inflation. It was recently argued that this "trans-Planckian problem" can never arise in a consistent string theory framework, which places a stringent constraint on the energy scale of inflation, $V^{1/4}\lesssim 10^9$ GeV. In this paper, we show that this requirement corresponds to a very small Hubble scale during inflation, $H_{\rm inf}\lesssim 1$ GeV, and therefore has serious consequences on scenarios where the dark matter d…
We show that the shape of the inflationary landscape potential may be constrained by analyzing cosmological data. The quantum fluctuations of fields orthogonal to the inflationary trajectory may have probed the structure of the local landscape potential, inducing non-Gaussianity (NG) in the primordial distribution of the curvature perturbations responsible for the cosmic microwave background (CMB) anisotropies and our Universe's large-scale structure. The resulting type of NG (tomographic NG) is determined by the shape of the landscape potential, and it cannot be fully characterized by 3- or 4…
We show that the constraints which follow from the {\it Trans-Planckian Censorship Conjecture} for inflationary cosmology can be strengthened if the pre-inflationary universe was dominated by radiation. The resulting upper bound on the energy scale of inflation is $η\sim 10^4 {\rm GeV}$, close to the scale accessible to accelerator experiments.
Constraining primordial oscillations and inflationary particle production with Planck, ACT DR6, and DESI DR2
David A. Dunlap Department of Astronomy & Astrophysics, University of Toronto（多伦多大学戴维·A·邓拉普天文学与天体物理学系）；Dunlap Institute for Astronomy and Astrophysics, University of Toronto（多伦多大学邓拉普天文学与天体物理学研究所）；School of Physics and Astronomy, Cardiff University（卡迪夫大学物理与天文学院）；Canadian Institute for Theoretical Astrophysics, University of Toronto（多伦多大学加拿大理论天体物理研究所）
Nonthermal leptogenesis via cosmological gravitational particle production is tested by inflationary gravitational waves
University of Manitoba（曼尼托巴大学）；Johns Hopkins University（约翰斯·霍普金斯大学）；The University of Chicago（芝加哥大学）；Rice University（莱斯大学）；University of Winnipeg（温尼伯大学）
In this short note, we pointed out that Warm inflationary scenario remains to be favoured over its cold counterpart by the recently proposed conjectures, which aim to overrule de Sitter like constructions in String Landscapes. On the other hand, the canonical cold (single-field slow-roll) inflationary models, which were in tension with the previously proposed de Sitter conjecture, have now become even more unlikely to realise in String Landscapes as these scenarios fail to cope up with both the conjectures, de Sitter and trans-Planckian censorship, at one go.
