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Register a new userTensions between direct measurements of the lens power spectrum from Planck data
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We apply a recently developed method to directly measure the gravitational lensing power spectrum from CMB power spectra to the Planck satellite data. This method allows us to analyze the tension between the temperature power spectrum and lens reconstruction in a model independent way. Even when allowing for arbitrary variations in the lensing power spectrum, the tension remains at the 2.4$sigma$ level. By separating the lensing and unlensed high redshift information in the CMB power spectra, we also show that under $Lambda$CDM the two are in tension at a similar level whereas the unlensed information is consistent with lensing reconstruction. These anomalies are driven by the smoother acoustic peaks relative to $Lambda$CDM at $ell sim 1250 - 1500$. Both tensions relax slightly when polarization data are considered. This technique also isolates the one aspect of the lensing power spectrum that the Planck CMB power spectra currently constrain and can be straightforwardly generalized to future data when CMB power spectra constrain multiple aspects of lensing which are themselves correlated with lensing reconstruction.
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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$sigma$. Between ACT and the South Pole Telescope (SPT) we find a tension of 2.4$sigma$, and 2.8$sigma$ 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 $Lambda$CDM standard model of the universe.
The primordial power spectrum describes the initial perturbations that seeded the large-scale structure we observe today. It provides an indirect probe of inflation or other structure-formation mechanisms. In this letter, we recover the primordial power spectrum from the Planck PR1 dataset, using our recently published algorithm PRISM. PRISM is a sparsity-based inversion method, that aims at recovering features in the primordial power spectrum from the empirical power spectrum of the cosmic microwave background (CMB). This ill-posed inverse problem is regularised using a sparsity prior on features in the primordial power spectrum in a wavelet dictionary. Although this non-parametric method does not assume a strong prior on the shape of the primordial power spectrum, it is able to recover both its general shape and localised features. As a results, this approach presents a reliable way of detecting deviations from the currently favoured scale-invariant spectrum. We applied PRISM to 100 simulated Planck data to investigate its performance on Planck-like data. We also tested the algorithms ability to recover a small localised feature at $k sim 0.125$ Mpc$^{-1}$, which caused a large dip at $ell sim 1800$ in the angular power spectrum. We then applied PRISM to the Planck PR1 power spectrum to recover the primordial power spectrum. We find no significant departures from the fiducial Planck PR1 near scale-invariant primordial power spectrum with $A_s=2.215times10^{-9}$ and $n_s = 0.9624$.
The cosmic expansion is computed for various dynamical vacuum models $Lambda(H)$ and confronted to the Cosmic Microwave Background (CMB) power spectrum from Planck. We also combined CMB in a joint analysis with other probes in order to place constraints on the cosmological parameters of the dynamical vacuum models. We find that all $Lambda(H)$ models are very efficient and in very good agreement with the data. Considering that the interaction term of the dark sector is given in terms of matter and radiation densities, we find that the corresponding $Lambda(H)$ model shows a small but non-zero deviation from $Lambda$ cosmology, nevertheless the confidence level is close to $sim 2.5sigma$.
We present the temperature power spectra of the cosmic microwave background (CMB) derived from the three seasons of data from the Atacama Cosmology Telescope (ACT) at 148 GHz and 218 GHz, as well as the cross-frequency spectrum between the two channels. We detect and correct for contamination due to the Galactic cirrus in our equatorial maps. We present the results of a number of tests for possible systematic error and conclude that any effects are not significant compared to the statistical errors we quote. Where they overlap, we cross-correlate the ACT and the South Pole Telescope (SPT) maps and show they are consistent. The measurements of higher-order peaks in the CMB power spectrum provide an additional test of the Lambda CDM cosmological model, and help constrain extensions beyond the standard model. The small angular scale power spectrum also provides constraining power on the Sunyaev-Zeldovich effects and extragalactic foregrounds. We also present a measurement of the CMB gravitational lensing convergence power spectrum at 4.6-sigma detection significance.
The most commonly used estimators of the anisotropic galaxy power spectrum employ Fast Fourier transforms, and rely on a specific choice of the line-of-sight that breaks the symmetry between the galaxy pair. This leads to wide-angle effects, including the presence of odd power spectrum multipoles like the dipole ($ell = 1$) and octopole ($ell = 3$). In Fourier-space these wide-angle effects also couple to the survey window function. We present a self-consistent framework extending the commonly used window function treatment to include the wide-angle effects. We show that our framework can successfully model the wide-angle effects in the BOSS DR12 dataset. We present estimators for the odd power spectrum multipoles and, detect these multipoles in BOSS DR12 with high significance. Understanding the impact of the wide-angle effects on the power spectrum multipoles is essential for many cosmological observables like primordial non-Gaussianity and the detection of General Relativistic effects and represents a potential systematic for measurements of Baryon Acoustic Oscillations and redshift-space distortions.
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