Testing cosmology with cosmic sound waves

Corasaniti, Pier-Stefano; Melchiorri, A.

doi:10.1103/physrevd.77.103507

Cited by 48 publications

(41 citation statements)

References 59 publications

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“…These two parameters capture most of the constraining power of the WMAP data for dark energy properties (Wang & Mukherjee 2007;Wright 2007;Elgarøy & Multamäki 2007;Corasaniti & Melchiorri 2008), with one important difference. The distance prior does not capture the information on the growth of structure probed by the late-time ISW effect.…”

Section: Wmap Distance Priormentioning

confidence: 99%

SEVEN-YEARWILKINSON MICROWAVE ANISOTROPY PROBE(WMAP) OBSERVATIONS: COSMOLOGICAL INTERPRETATION

Komatsu¹,

Smith²,

Dunkley³

et al. 2011

ApJS

7,710

472

6,429

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The combination of seven-year data from WMAP and improved astrophysical data rigorously tests the standard cosmological model and places new constraints on its basic parameters and extensions. By combining the WMAP data with the latest distance measurements from the baryon acoustic oscillations (BAO) in the distribution of galaxies and the Hubble constant (H 0 ) measurement, we determine the parameters of the simplest six-parameter ΛCDM model. The power-law index of the primordial power spectrum is n s = 0.968 ± 0.012 (68% CL) for this data combination, a measurement that excludes the Harrison-Zel'dovich-Peebles spectrum by 99.5% CL. The other parameters, including those beyond the minimal set, are also consistent with, and improved from, the five-year results. We find no convincing deviations from the minimal model. The seven-year temperature power spectrum gives a better determination of the third acoustic peak, which results in a better determination of the redshift of the matter-radiation equality epoch. Notable examples of improved parameters are the total mass of neutrinos, m ν < 0.58 eV (95% CL), and the effective number of neutrino species, N eff = 4.34 +0.86 −0.88 (68% CL), which benefit from better determinations of the third peak and H 0 . The limit on a constant dark energy equation of state parameter from WMAP+BAO+H 0 , without high-redshift Type Ia supernovae, is w = −1.10 ± 0.14 (68% CL). We detect the effect of primordial helium on the temperature power spectrum and provide a new test of big bang nucleosynthesis by measuring Y p = 0.326 ± 0.075 (68% CL). We detect, and show on the map for the first time, the tangential and radial polarization patterns around hot and cold spots of temperature fluctuations, an important test of physical processes at z = 1090 and the dominance of adiabatic scalar fluctuations. The seven-year polarization data have significantly improved: we now detect the temperature-E-mode polarization cross power spectrum at 21σ , compared with 13σ from the five-year data. With the seven-year temperature-B-mode cross power spectrum, the limit on a rotation of the polarization plane due to potential parity-violating effects has improved by 38% to Δα = −1.• 1 ± 1.• 4(statistical) ± 1.• 5(systematic) (68% CL). We report significant detections of the Sunyaev-Zel'dovich (SZ) effect at the locations of known clusters of galaxies. The measured SZ signal agrees well with the expected signal from the X-ray data on a cluster-by-cluster basis. However, it is a factor of 0.5-0.7 times the predictions from "universal profile" of Arnaud et al., analytical models, and hydrodynamical simulations. We find, for the first time in the SZ effect, a significant difference between the cooling-flow and non-cooling-flow clusters (or relaxed and non-relaxed clusters), which can explain some of the discrepancy. This lower amplitude is consistent with the lower-than-theoretically expected SZ power spectrum recently measured by the South Pole Telescope Collaboration.

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Section: Wmap Distance Priormentioning

confidence: 99%

SEVEN-YEARWILKINSON MICROWAVE ANISOTROPY PROBE(WMAP) OBSERVATIONS: COSMOLOGICAL INTERPRETATION

Komatsu¹,

Smith²,

Dunkley³

et al. 2011

ApJS

7,710

472

6,429

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“…[22][23][24] have studied this point in more detail and found that the constraints on R are relatively stable under minor modifications of the dark energy parameters underlying the analysis, including dark energy clustering [24]. It was found that massive neutrinos had a larger effect on R (few percent level) [24]. In Ref.…”

Section: Cmb Measurementsmentioning

confidence: 97%

Nonparametric reconstruction of the dark energy equation of state from diverse data sets

et al. 2011

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The cause of the accelerated expansion of the Universe poses one of the most fundamental questions in physics today. In the absence of a compelling theory to explain the observations, a first task is to develop a robust phenomenological approach: If the acceleration is driven by some form of dark energy, then, the phenomenology is determined by the form of the dark energy equation of state w(z) as a function of redshift. A major aim of ongoing and upcoming cosmological surveys is to measure w and its evolution at high accuracy. Since w(z) is not directly accessible to measurement, powerful reconstruction methods are needed to extract it reliably from observations. We have recently introduced a new reconstruction method for w(z) based on Gaussian process modeling. This method can capture nontrivial w(z) dependences and, most importantly, it yields controlled and unbiased error estimates. In this paper we extend the method to include a diverse set of measurements: baryon acoustic oscillations, cosmic microwave background measurements, and supernova data. We analyze currently available data sets and present the resulting constraints on w(z), finding that current observations are in very good agreement with a cosmological constant. In addition we explore how well our method captures nontrivial behavior of w(z) by analyzing simulated data assuming high-quality observations from future surveys. We find that the baryon acoustic oscillation measurements by themselves already lead to remarkably good reconstruction results and that the combination of different high-quality probes allows us to reconstruct w(z) very reliably with small error bounds.

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“…We specifically use the CMB-only bandpowers described in this paper and available in the Planck Legacy Archive 24 , adopting the same weighting scheme within each bin. Fitting for the positions and amplitudes of features in the band-powers is a topic with a long history, with approaches becoming more sophisticated as the fidelity of the data improved (e.g., Scott & White 1994;Hancock & Rocha 1997;Knox & Page 2000;de Bernardis et al 2002;Bond et al 2003;Page et al 2003;Benoît et al 2003;Durrer et al 2003;Readhead et al 2004;Jones et al 2006;Hinshaw et al 2007;Corasaniti & Melchiorri 2008;Pryke et al 2009). Following earlier approaches, we fit Gaussian functions to the peaks and troughs in C T T and C EE , but parabolas for the C TE features.…”

Section: Appendix D: High-likelihood Supplementmentioning

confidence: 99%

Planck2015 results

Aghanim

Arnaud

Ashdown

et al. 2016

A&A

669

339

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This paper presents the Planck 2015 likelihoods, statistical descriptions of the 2-point correlation functions of the cosmic microwave background (CMB) temperature and polarization fluctuations that account for relevant uncertainties, both instrumental and astrophysical in nature. They are based on the same hybrid approach used for the previous release, i.e., a pixel-based likelihood at low multipoles ( < 30) and a Gaussian approximation to the distribution of cross-power spectra at higher multipoles. The main improvements are the use of more and better processed data and of Planck polarization information, along with more detailed models of foregrounds and instrumental uncertainties. The increased redundancy brought by more than doubling the amount of data analysed enables further consistency checks and enhanced immunity to systematic effects. It also improves the constraining power of Planck, in particular with regard to small-scale foreground properties. Progress in the modelling of foreground emission enables the retention of a larger fraction of the sky to determine the properties of the CMB, which also contributes to the enhanced precision of the spectra. Improvements in data processing and instrumental modelling further reduce uncertainties. Extensive tests establish the robustness and accuracy of the likelihood results, from temperature alone, from polarization alone, and from their combination. For temperature, we also perform a full likelihood analysis of realistic end-to-end simulations of the instrumental response to the sky, which were fed into the actual data processing pipeline; this does not reveal biases from residual low-level instrumental systematics. Even with the increase in precision and robustness, the ΛCDM cosmological model continues to offer a very good fit to the Planck data. The slope of the primordial scalar fluctuations, n s , is confirmed smaller than unity at more than 5σ from Planck alone. We further validate the robustness of the likelihood results against specific extensions to the baseline cosmology, which are particularly sensitive to data at high multipoles. For instance, the effective number of neutrino species remains compatible with the canonical value of 3.046. For this first detailed analysis of Planck polarization spectra, we concentrate at high multipoles on the E modes, leaving the analysis of the weaker B modes to future work. At low multipoles we use temperature maps at all Planck frequencies along with a subset of polarization data. These data take advantage of Planck's wide frequency coverage to improve the separation of CMB and foreground emission. Within the baseline ΛCDM cosmology this requires τ = 0.078 ± 0.019 for the reionization optical depth, which is significantly lower than estimates without the use of high-frequency data for explicit monitoring of dust emission. At high multipoles we detect residual systematic errors in E polarization, typically at the µK 2 level; we therefore choose to retain temperature information alone for high multipoles a...

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Testing cosmology with cosmic sound waves

Cited by 48 publications

References 59 publications

SEVEN-YEARWILKINSON MICROWAVE ANISOTROPY PROBE(WMAP) OBSERVATIONS: COSMOLOGICAL INTERPRETATION

SEVEN-YEARWILKINSON MICROWAVE ANISOTROPY PROBE(WMAP) OBSERVATIONS: COSMOLOGICAL INTERPRETATION

Nonparametric reconstruction of the dark energy equation of state from diverse data sets

Planck2015 results

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