Planck2018 results

Abstract

We present measurements of the cosmic microwave background (CMB) lensing potential using the final Planck 2018 temperature and polarization data. Using polarization maps filtered to account for the noise anisotropy, we increase the significance of the detection of lensing in the polarization maps from 5σ to 9σ. Combined with temperature, lensing is detected at 40σ. We present an extensive set of tests of the robustness of the lensing-potential power spectrum, and construct a minimum-variance estimator likelihood over lensing multipoles 8 ≤ L ≤ 400 (extending the range to lower L compared to 2015), which we use to constrain cosmological parameters. We find good consistency between lensing constraints and the results from the Planck CMB power spectra within the ΛCDM model. Combined with baryon density and other weak priors, the lensing analysis alone constrains σ8Ωm0.25 = 0.589 ± 0.020 (1σ errors). Also combining with baryon acoustic oscillation data, we find tight individual parameter constraints, σ8 = 0.811 ± 0.019, H0 = 67.9−1.3+1.2 km s−1 Mpc−1, and Ωm = 0.303−0.018+0.016. Combining with Planck CMB power spectrum data, we measure σ8 to better than 1% precision, finding σ8 = 0.811 ± 0.006. CMB lensing reconstruction data are complementary to galaxy lensing data at lower redshift, having a different degeneracy direction in σ8 − Ωm space; we find consistency with the lensing results from the Dark Energy Survey, and give combined lensing-only parameter constraints that are tighter than joint results using galaxy clustering. Using the Planck cosmic infrared background (CIB) maps as an additional tracer of high-redshift matter, we make a combined Planck-only estimate of the lensing potential over 60% of the sky with considerably more small-scale signal. We additionally demonstrate delensing of the Planck power spectra using the joint and individual lensing potential estimates, detecting a maximum removal of 40% of the lensing-induced power in all spectra. The improvement in the sharpening of the acoustic peaks by including both CIB and the quadratic lensing reconstruction is detected at high significance.

2020 global reassessment of the neutrino oscillation picture

“…In our analyses, we consider the most recent observations of the CMB spectrum by Planck [108,109], which measures the temperature and polarization spectra in a wide range of multipoles through the respective two-point correlation functions [110] and the lensing [111] potential through the four-point correlation function. We include BAO observations from the 6dF [112], SDSS DR7 Main Galaxy Sample (MGS) [113] and BOSS DR12 [114] galaxy redshift surveys.…”

Post-Newtonian limit of generalized scalar-torsion theories of gravity

“…During the last century the general theory of relativity, which conventionally attributes the gravitational interaction to the curvature of spacetime, encoded in the presence of the Ricci scalar R in the action, has passed most of the tests given by solar system and astrophysical observations [1][2][3][4][5][6][7][8]. Several observations in cosmology and the dynamics of large scale structures, however, are unexplained within general relativity itself, unless it is supplemented with additional, "dark" components [9][10][11][12][13][14][15][16][17][18][19]. These open questions, as well as the quest for a quantum theory of gravity, have motivated the construction and investigation of several modifications and alternatives to general relativity [20][21][22].…”

A demonstration of improved constraints on primordial gravitational waves with delensing

“…In other work, lensing templates have also been constructed after transforming to harmonic space, converting to E=B, and lensing by a ϕ tracer using expressions derived from the first-order Taylor expansion of Eq. (1) [16,18,19]. At the noise levels of the current analysis, the two approaches perform similarly in constraining the lensing B-mode contribution to the observed B-modes.…”

“…Given an estimate of the projected gravitational potential responsible for CMB lensing and the observed CMB E-mode pattern, one can estimate the B-modes which have been produced by the lensing effect. Subtracting these from the observed B-modes has been demonstrated to reduce B-mode power in several recent works [16][17][18][19][20]. However, none of these works have demonstrated a reduction in the B-mode measurement uncertainties at large angular scales-a necessary step to achieve improved constraints on PGWs.…”

“…However, since the lensing potential is a weighted integral of the mass distribution along the line of sight between us and the last scattering surface, we may also approximate it by other tracers of this mass distribution. At the noise levels of current CMB observations, it turns out to be better to use a cosmic infrared background (CIB) [22,23] map rather than one of the available CMB lensing reconstructions [18,24] directly. To use an alternate tracer of ϕ, we need to know the degree of correlation between it and the true CMB lensing potential-if this were misestimated it could potentially lead to a false detection of PGW.…”