When combining cosmological and oscillations results to constrain the neutrino sector, the question of the propagation of systematic uncertainties is often raised. We address this issue in the ...context of the derivation of an upper bound on the sum of the neutrino masses (Σmν) with recent cosmological data. This work is performed within the ΛCDM model extended to Σmν, for which we advocate the use of three mass-degenerate neutrinos. We focus on the study of systematic uncertainties linked to the foregrounds modelling in cosmological microwave background (CMB) data analysis, and on the impact of the present knowledge of the reionisation optical depth. This is done through the use of different likelihoods built from Planck data. Limits on Σmν are derived with various combinations of data, including the latest baryon acoustic oscillations (BAO) and Type Ia supernovae (SNIa) results. We also discuss the impact of the preference for current CMB data for amplitudes of the gravitational lensing distortions higher than expected within the ΛCDM model, and add the Planck CMB lensing. We then derive a robust upper limit: Σmν< 0.17 eV at 95% CL, including 0.01eV of foreground systematics. We also discuss the neutrino mass repartition and show that today’s data do not allow one to disentangle normal from inverted hierarchy. The impact on the other cosmological parameters is also reported, for different assumptions on the neutrino mass repartition, and different high and low multipole CMB likelihoods.
nsions in cosmological parameters measurement motivate a revisit of the effects of instrumental systematics. In this article, we focus on the Pearson's correlation coefficient of the cosmic microwave ...background temperature and polarization E modes RℓTE, which has the property of not being biased by multiplicative instrumental systematics. We build a RℓTE-based likelihood for the Planck data and present the first constraints on Λ CDM (Lambda cold dark matter) parameters from the correlation coefficient. Our results are compatible with parameters derived from a power-spectra-based likelihood. In particular, the value of the Hubble parameter H0 characterizing the expansion of the Universe today, 67.5 ± 1.3 km / s / Mpc , is consistent with the ones inferred from standard cosmic microwave background analysis. We also discuss the consistency of the Planck correlation coefficient with the one computed from the most recent ACTPol power spectra.
The quadratic maximum likelihood estimator can be used to reconstruct the cosmic microwave background (CMB) power spectra with minimal error bars. Still, it requires an accurate estimate of the data ...set’s noise covariance matrix in order to be corrected for spurious bias. We describe an extension of this method to cross-correlation, thus removing noise bias and mitigating the impact of systematic effects, providing that they are uncorrelated. This estimator is tested on two simulation surveys at large and intermediate angular scales, respectively corresponding to satellite and ground-based CMB experiments. The analysis focuses on polarization maps, over a wide range of noise levels from 0.1 to 50 μK arcmin. We show how this estimator minimizes the increase of variance due to polarization leakage between E and B modes. We compare this method with the pure pseudospectrum formalism, which is computationally faster but less optimal, especially on large angular scales.
We demonstrate that the cosmic microwave background (CMB) temperature-polarization cross-correlation provides accurate and robust constraints on cosmological parameters. We compare them with the ...results from temperature or polarization and investigate the impact of foregrounds, cosmic variance, and instrumental noise. This analysis makes use of the Planck high-ℓ HiLLiPOP likelihood based on angular power spectra, which takes into account systematics from the instrument and foreground residuals directly modelled using Planck measurements. The temperature-polarization correlation (TE) spectrum is less contaminated by astrophysical emissions than the temperature power spectrum (TT), allowing constraints that are less sensitive to foreground uncertainties to be derived. For ΛCDM parameters, TE gives very competitive results compared to TT. For basic ΛCDM model extensions (such as AL, ∑mν, or Neff), it is still limited by the instrumental noise level in the polarization maps.
The angular power spectra of the cosmic microwave background (CMB) temperature anisotropies reconstructed from Planck data seem to present “too much” gravitational lensing distortion. This is ...quantified by the control parameter AL that should be compatible with unity for a standard cosmology. With the class Boltzmann solver and the profile-likelihood method, for this parameter we measure a 2.6σ shift from 1 using the Planck public likelihoods. We show that, owing to strong correlations with the reionization optical depth τ and the primordial perturbation amplitude As, a ~ 2σ tension on τ also appears between the results obtained with the low (ℓ ≤ 30) and high (30 < ℓ ≲ 2500) multipoles likelihoods. With Hillipop, another high-ℓ likelihood built from Planck data, this difference is lowered to 1.3σ. In this case, the AL value is still in disagreement with unity by 2.2σ, suggesting a non-trivial effect of the correlations between cosmological and nuisance parameters. To better constrain the nuisance foregrounds parameters, we include the very-high-ℓ measurements of the Atacama Cosmology Telescope (ACT) and South Pole Telescope (SPT) experiments and obtain AL = 1.03 ± 0.08. The Hillipop+ACT+SPT likelihood estimate of the optical depth is τ = 0.052 ± 0.035, which is now fully compatible with the low-ℓ likelihood determination. After showing the robustness of our results with various combinations, we investigate the reasons for this improvement that results from a better determination of the whole set of foregrounds parameters. We finally provide estimates of the Λ cold dark matter parameters with our combined CMB data likelihood.
In this paper, we study the estimation of the effective number of relativistic species from a combination of cosmic microwave background (CMB) and baryon acoustic oscillations (BAO) data. We vary ...different ingredients of the analysis: the
Planck
high-
ℓ
likelihoods, the Boltzmann solvers, and the statistical approaches. The variation of the inferred values gives an indication of an additional systematic uncertainty, which is of the same order of magnitude as the error derived from each individual likelihood. We show that this systematic uncertainty is essentially associated to the assumptions made in the high-
ℓ
likelihood implementations, in particular for the foreground residuals modellings. We also compare a subset of likelihoods using only the TE power spectra, expected to be less sensitive to foreground residuals.
We present cosmological parameter constraints using maps from the last
Planck
data release (PR4). In particular, we detail an upgraded version of the cosmic microwave background likelihood,
HiLLiPoP
..., that is based on angular power spectra and relies on a physical modeling of the foreground residuals in the spectral domain. This new version of the likelihood retains a larger sky fraction (up to 75%) and uses an extended multipole range. Using this likelihood, along with low-
ℓ
measurements from
LoLLiPoP
, we derived constraints on ΛCDM parameters that are in good agreement with previous
Planck
2018 results, but with smaller uncertainties by 10% to 20%. We demonstrate that the foregrounds can be accurately described in the spectral domain, with a negligible impact on ΛCDM parameters. We also derived constraints on single-parameter extensions to ΛCDM, including
A
L
, Ω
K
,
N
eff
, and ∑
m
ν
. Noteworthy results from this updated analysis include a lensing amplitude value of
A
L
= 1.039 ± 0.052, which is more closely aligned with theoretical expectations within the ΛCDM framework. Additionally, our curvature measurement, Ω
K
= −0.012 ± 0.010, is now fully consistent with a flat universe and our measurement of
S
8
is closer to the measurements derived from large-scale structure surveys (at the 1.5
σ
level). We also added constraints from PR4 lensing, making this combination the most tightly constrained data set currently available from
Planck
. Additionally, we explored the addition of baryon acoustic oscillation data, which tightens the limits on some particular extensions to the standard cosmology.
The High Frequency Instrument of Planck will map the entire sky in the millimeter and sub-millimeter domain from 100 to 857 GHz with unprecedented sensitivity to polarization (ΔP/Tcmb ~ 4 × 10-6 ...for P either Q or U and Tcmb $\simeq$ 2.7 K) at 100, 143, 217 and 353 GHz. It will lead to major improvements in our understanding of the cosmic microwave background anisotropies and polarized foreground signals. Planck will make high resolution measurements of the E-mode spectrum (up to $\ell$ ~ 1500) and will also play a prominent role in the search for the faint imprint of primordial gravitational waves on the CMB polarization. This paper addresses the effects of calibration of both temperature (gain) and polarization (polarization efficiency and detector orientation) on polarization measurements. The specific requirements on the polarization parameters of the instrument are set and we report on their pre-flight measurement on HFI bolometers. We present a semi-analytical method that exactly accounts for the scanning strategy of the instrument as well as the combination of different detectors. We use this method to propagate errors through to the CMB angular power spectra in the particular case of Planck-HFI, and to derive constraints on polarization parameters. We show that in order to limit the systematic error to 10% of the cosmic variance of the E-mode power spectrum, uncertainties in gain, polarization efficiency and detector orientation must be below 0.15%, 0.3% and 1° respectively. Pre-launch ground measurements reported in this paper already fulfill these requirements.
In this paper, we study the estimation of the effective number of relativistic species from a combination of cosmic microwave background (CMB) and baryon acoustic oscillations (BAO) data. We vary ...different ingredients of the analysis: the Planck high-ℓ likelihoods, the Boltzmann solvers, and the statistical approaches. The variation of the inferred values gives an indication of an additional systematic uncertainty, which is of the same order of magnitude as the error derived from each individual likelihood. We show that this systematic uncertainty is essentially associated to the assumptions made in the high-ℓ likelihood implementations, in particular for the foreground residuals modellings. We also compare a subset of likelihoods using only the TE power spectra, expected to be less sensitive to foreground residuals.
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