Parameter discordance in Planck CMB and low-redshift measurements: projection in the primordial power spectrum

Hazra, Dhiraj Kumar; Shafieloo, Arman; Souradeep, T.

doi:10.1088/1475-7516/2019/04/036

Cited by 40 publications

(38 citation statements)

References 39 publications

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“…Explanations for the tension between direct measurements and CMB estimates range from underestimated systematic errors or modeling of the primordial power spectrum (e.g., Davis et al 2019;Dhawan et al 2020;Anderson 2019;Hazra et al 2019), to models for dark energy (e.g., Li & Shafieloo 2019;Alestas et al 2020;Di Valentino et al 2020), to unmodeled pre-recombination physics that lead to a decreased sound horizon scale (e.g., Poulin et al 2019;Chiang & Slosar 2018;Beradze & Gogberashvili 2020;Vagnozzi 2019;Lin et al 2019;Arendse et al 2019). See Knox & Millea (2020) for a review of possible solutions to the tension.…”

Section: Bao and The H 0 Tensionmentioning

confidence: 99%

Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Cosmological implications from two decades of spectroscopic surveys at the Apache Point Observatory

Alam¹,

Aubert²,

Ávila³

et al. 2021

Phys. Rev. D

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We present the cosmological implications from final measurements of clustering using galaxies, quasars, and Lyα forests from the completed Sloan Digital Sky Survey (SDSS) lineage of experiments in large-scale structure. These experiments, composed of data from SDSS, SDSS-II, BOSS, and eBOSS, offer independent measurements of baryon acoustic oscillation (BAO) measurements of angular-diameter distances and Hubble distances relative to the sound horizon, r d , from eight different samples and six measurements of the growth rate parameter, f σ 8 , from redshift-space distortions (RSD). This composite sample is the most constraining of its kind and allows us to perform a comprehensive assessment of the cosmological model after two decades of dedicated spectroscopic observation. We show that the BAO data alone are able to rule out dark-energy-free models at more than eight standard deviations in an extension to the flat, ΛCDM model that allows for curvature. When combined with Planck Cosmic Microwave Background (CMB) measurements of temperature and polarization, under the same model, the BAO data provide nearly an order of magnitude improvement on curvature constraints relative to primary CMB constraints alone. Independent of distance measurements, the SDSS RSD data complement weak lensing measurements from the Dark Energy Survey (DES) in demonstrating a preference for a flat ΛCDM cosmological model when combined with Planck measurements. The RSD and lensing measurements indicate a growth rate that is consistent with predictions from Planck temperature and polarization data and with General Relativity. When combining the results of SDSS BAO and RSD, Planck, Pantheon Type Ia supernovae (SNe Ia), and DES weak lensing and clustering measurements, all multiple-parameter extensions remain consistent with a ΛCDM model. Regardless of cosmological model, the precision on each of the three ΛCDM parameters, Ω Λ , H 0 , and σ 8 , remains at roughly 1%, showing changes of less than 0.6% in the central values between models. In a model that allows for free curvature and a time-evolving equation of state for dark energy, the combined samples produce a constraint Ω k = −0.0023 ± 0.0022. The dark energy constraints lead to w 0 = −0.912 ± 0.081 and w a = −0.48 +0.36 −0.30 , corresponding to an equation of state of w p = −1.020 ± 0.032 at a pivot redshift z p = 0.29 and a Dark Energy Figure of Merit of 92. The inverse distance ladder measurement under this model yields H 0 = 68.20 ± 0.81 km s −1 Mpc −1 , remaining in tension with several direct determination methods; the BAO data allow Hubble constant estimates that are robust against the assumption of the cosmological model. In addition, the BAO data allow estimates of H 0 that are independent of the CMB data, with similar central values and precision under a ΛCDM model. Our most constraining combination of data gives the upper limit on the sum of neutrino masses at m ν < 0.111 eV (95% confidence). Finally, we consider the improvements in cosmology constraints over the last decade by...

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Section: Bao and The H 0 Tensionmentioning

confidence: 99%

Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Cosmological implications from two decades of spectroscopic surveys at the Apache Point Observatory

Alam¹,

Aubert²,

Ávila³

et al. 2021

Phys. Rev. D

Self Cite

888

600

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“…We can clearly see the improvement in the reconstruction accuracy, with the NIRL version more or less exactly approaching the ideal reconstruction. The summary of the test results are given in table 6…”

Section: Significantmentioning

confidence: 99%

“…There have been model construction based approaches, such as [4,5], both to explain low features as well as address possible high features such as lensing excess in C T T . Recent work has focussed on analyzing the the H 0 tension in context of a free-form P R (k) reconstruction using the improved Richardson-Lucy (IRL) deconvolution algorithm [6,17] as well as for general feature hunting. There are also other free-form and other reconstruction methods that have been developed [11,[36][37][38][39][40]43].…”

Section: Introductionmentioning

confidence: 99%

“…Since a free-form fitting is likely to risk the possibility of over-fitting or fitting of noise, this necessitates a level of precision over the reconstruction algorithm that is capable of discerning and filtering out such effects while being able to probe actual data. The effect of weak lensing acoustic peak smoothing of the C T T L power spectrum has been been demonstrated and discussed in context of IRL based P R (k) reconstruction earlier [6,16]. Weak lensing when not considered, can easily produce artefacts at high k in the P R (k) and is degenerate with any physical origin deviations from power law in P R (k) and has to be accounted for.…”

Section: Introductionmentioning

confidence: 99%

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Primordial Power Spectrum from Lensed CMB Temperature Spectrum using Iterative Delensing

Sushovan¹,

Souradeep²

2021

Preprint

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We address a current caveat in the deconvolution of the Primordial Power Spectrum (PPS), from observed Cosmic Microwave Background (CMB) temperature anisotropy, in the presence of weak lensing of the CMB by the large scale structure (LSS) in the Universe. We propose a modification to the popular Richardson-Lucy (RL) deconvolution algorithm used in the context of reconstructing a free-form PPS, P R (k) from observed lensed CMB temperature anisotropy power spectrum C T T . We show that the modified RL algorithm works in the context of a non-linear convolution problem, such as in the case of weak lensing. The Non-Linear Iterative Richardson-Lucy (NIRL) algorithm is successful at both convergence, as well as fidelity, in reconstructing features in some underlying PPS. This makes PPS reconstruction efforts more robust in the context of lensed CMB temperature observations. No prior assumptions on the PPS are involved during the iterative delensing process, and distinct improvement is noted over a power-law template based delensing approach used earlier, at the cost of moderately increased computational cost due to the NIRL reconstruction.

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“…For instance, one can consider the possibility that discrepancy between low redshift measurements of H0 and those obtained from CMB observations can be projected onto a primordial power spectrum with specific features[79].…”

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confidence: 99%

Reconstructing the EFT of inflation from cosmological data

Durakovic

Hunt²,

Patil³

et al. 2019

SciPost Phys.

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Reconstructions of the primordial power spectrum (PPS) of curvature perturbations from cosmic microwave background anisotropies and large-scale structure data suggest that the usually assumed power-law PPS has localised features (up to ∼ 10% in amplitude), although of only marginal significance in the framework of ΛCDM cosmology. On the other hand if the cosmology is taken to be Einstein-de Sitter, larger features in the PPS (up to ∼ 20% in amplitude) are required to accurately fit the observed acoustic peaks. Within the context of single clock inflation, we show that any given reconstruction of the PPS can be mapped on to functional parameters of the underlying effective theory of the adiabatic mode within a 2ndorder formalism, provided the best fit fractional change of the PPS, ∆P R /P R is such that (∆P R /P R ) 3 falls within the 1 σ confidence interval of the reconstruction for features induced by variations of either the sound speed c s or the slow-roll parameter . Although there is a degeneracy amongst these functional parameters (and the models that project onto them), we can identify simple representative inflationary models that yield such features in the PPS. Thus we provide a dictionary (more accurately, a thesaurus) to go from observational data, via the reconstructed PPS, to models that reproduce them to per cent level precision.

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Parameter discordance in Planck CMB and low-redshift measurements: projection in the primordial power spectrum

Cited by 40 publications

References 39 publications

Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Cosmological implications from two decades of spectroscopic surveys at the Apache Point Observatory

Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Cosmological implications from two decades of spectroscopic surveys at the Apache Point Observatory

Primordial Power Spectrum from Lensed CMB Temperature Spectrum using Iterative Delensing

Reconstructing the EFT of inflation from cosmological data

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