Cosmology in the era of Euclid and the Square Kilometre Array

Sprenger, Tim; Archidiacono, Maria; Brinckmann, Thejs; Clesse, S.; Lesgourgues, Julien

doi:10.1088/1475-7516/2019/02/047

Cited by 125 publications

(196 citation statements)

References 111 publications

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“…Importantly, the precision of the shape parameter measurements from these surveys will be comparable to that of Planck, and the combination of the two will reduce the errorbars by a factor of few due to degeneracy breaking [34]. This effect will be essential for the future neutrino mass measurements [28,34,[75][76][77][78][79]. The presented constraints set a reference mark for future LSS and CMB observations that will surpass Planck and BOSS.…”

Section: Discussionmentioning

confidence: 99%

Cosmological parameters and neutrino masses from the final Planck and full-shape BOSS data

2020

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We present a joint analysis of the Planck cosmic microwave background (CMB) and Baryon Oscillation Spectroscopic Survey (BOSS) final data releases. A key novelty of our study is the use of a new full-shape (FS) likelihood for the redshift-space galaxy power spectrum of the BOSS data, based on an improved perturbation theory template. We show that the addition of the redshift space galaxy clustering measurements breaks degeneracies present in the CMB data alone and tightens constraints on cosmological parameters. Assuming the minimal ΛCDM cosmology with massive neutrinos, we find the following late-Universe parameters: the Hubble constant H0 = 67.95 +0.66 −0.52 km s −1 Mpc −1 , the matter density fraction Ωm = 0.3079 +0.0065 −0.0085 , the mass fluctuation amplitude σ8 = 0.8087 +0.012 −0.0072 , and an upper limit on the sum of neutrino masses Mtot < 0.16 eV (95% CL). This can be contrasted with the Planck-only measurements: H0 = 67.14 +1.3 −0.72 km s −1 Mpc −1 , Ωm = 0.3188 +0.0091 −0.016 , σ8 = 0.8053 +0.019 −0.0091 , and Mtot < 0.26 eV (95% CL). Our bound on the sum of neutrino masses relaxes once the hierarchy-dependent priors from the oscillation experiments are imposed. The addition of the new FS likelihood also constrains the effective number of extra relativistic degrees of freedom, N eff = 2.88 ± 0.17. Our study shows that the current FS and the pure baryon acoustic oscillation data add a similar amount of information in combination with the Planck likelihood. We argue that this is just a coincidence given the BOSS volume and efficiency of the current reconstruction algorithms. In the era of future surveys FS will play a dominant role in cosmological parameter measurements.

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Section: Discussionmentioning

confidence: 99%

Cosmological parameters and neutrino masses from the final Planck and full-shape BOSS data

2020

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“…We will now move on to present an MCMC analysis using the monopole, quadrupole, and hexadecapole spectra. An MCMC analysis is generally expected to be more reliable than Fisher matrix forecasts, as it can probe non-Gaussian posteriors and does not suffer from numerical instabilities that can sometimes be encountered in Fisher analyses [67]. It also closely resembles a real data analysis procedure, and allows us to study biases on the estimation of the cosmological parameter of interest, f [36].…”

Section: Eftoflss-based Model Forecastsmentioning

confidence: 99%

Assessing non-linear models for galaxy clustering – II. Model validation and forecasts for Stage IV surveys

Bose

Pourtsidou

Markovič

et al. 2020

Monthly Notices of the Royal Astronomical Society

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We provide a detailed comparison of two different models for the halo redshift space power spectrum, namely the commonly applied TNS model and an effective field theory of large scale structure (EFTofLSS) inspired model. In a least χ 2 analysis using simulation data, we determine ranges of validity for the models. In all our analyses we vary all nuisance parameters and the growth rate of structure, f , using survey specifications typical of Stage IV galaxy surveys. We determine that the TNS model with a Lorentzian damping and using standard Eulerian perturbative modelling outperforms other variants of the TNS model. But we also find that the EFTofLSS-based model is able to fit the data down to smaller scales compared to this optimal TNS variant at z = 0.5, while the two models perform equally well at z = 1. We then conduct an exploratory Fisher analysis to investigate parameter degeneracies, using the full anisotropic power spectrum. Next, we move on to a Bayesian MCMC analysis utilising the monopole, quadrupole, and hexadecapole spectra, with a restricted range of scales for the latter in order for the f constraints to remain unbiased. In contrast to the exploratory Fisher matrix forecasts, our MCMC analysis finds that the EFTofLSS-based model provides tighter marginalised constraints on the growth rate at z = 0.5 than the TNS model, despite having additional nuisance parameters. The two perform comparatively at z = 1. We also investigate the impact of priors on nuisance parameters which can be reasonably obtained from higher order statistics or external data sets. We find that conservative priors have limited impact on the constraints. Finally, we extend previous work to provide a consistent comparison between Fisher matrix and MCMC forecasts for the EFTofLSS model using the multipole expansion formalism, and reach good agreement between them.

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“…These corrections can be estimated and added to the covariance matrix as a correlated error [20]. This treatment is different from a usually employed approach of trusting the theory completely until a certain wavenumber k max [39,[51][52][53][54]. Using such a cut-off means that all information coming from wavenumbers higher than k max is thrown away.…”

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confidence: 99%

Measuring neutrino masses with large-scale structure: Euclid forecast with controlled theoretical error

Chudaykin

Ivanov

2019

J. Cosmol. Astropart. Phys.

152

171

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We present a Markov-Chain Monte-Carlo (MCMC) forecast for the precision of neutrino mass and cosmological parameter measurements with a Euclidlike galaxy clustering survey. We use a complete perturbation theory model for the galaxy one-loop power spectrum and tree-level bispectrum, which includes bias, redshift space distortions, IR resummation for baryon acoustic oscillations and UV counterterms. The latter encapsulate various effects of short-scale dynamics which cannot be modeled within perturbation theory. Our MCMC procedure consistently computes the non-linear power spectra and bispectra as we scan over different cosmologies. The second ingredient of our approach is the theoretical error covariance which captures uncertainties due to higher-order non-linear corrections omitted in our model. Having specified characteristics of a Euclid-like spectroscopic survey, we generate and fit mock galaxy power spectrum and bispectrum likelihoods. Our results suggest that even under very agnostic assumptions about non-linearities and short-scale physics a future Euclid-like survey will be able to measure the sum of neutrino masses with a standard deviation of 28 meV. When combined with the most recent Planck likelihood, this uncertainty decreases to 19 meV. Reducing the theoretical error on the bispectrum down to the two-loop level marginally tightens the bound to 17 meV. 1 chudy@ms2.inr.ac.ru 2 mi1271@nyu.edu arXiv:1907.06666v1 [astro-ph.CO] 15 Jul 2019 exploit the potential of upcoming surveys will strongly depend on the understanding on these effects, which is not yet complete.Fortunately, the bulk of information about the neutrino free-streaming is encoded in mildly non-linear scales which can be robustly and systematically described within perturbation theory. One of the most popular approaches is Eulerian standard cosmological perturbation theory (SPT) [14]. The basic formulation of SPT, however, does not correctly capture the non-linear evolution of baryon acoustic oscillations (BAO) [15] and short-scale physics beyond the single-stream pressureless perfect fluid hydrodynamics [16][17][18]. These problems have been intensely studied in the recent years.First, it has been shown that the non-linear suppression and distortion of the BAO can be captured by a resummation of contributions describing the tidal effects of large-scale bulk flows. This procedure, called infrared (IR) resummation, is essential for an accurate description of the BAO and has been formulated within various theoretical frameworks [19][20][21][22][23][24][25]. We will adopt a systematic approach of [22,24] streamlined in the context of time-sliced perturbation theory [26].Second, we will use the effective field theory of large-scale structure (EFT) to account for the back-reaction of small scale nonlinearities on larger scales [17,27,28]. This approach removes the unphysical UV sensitivity of perturbation theory loop integrals and parameterizes the ignorance about short scale-dynamics by various effective operators in the equations of motion for ...

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Cosmology in the era of Euclid and the Square Kilometre Array

Cited by 125 publications

References 111 publications

Cosmological parameters and neutrino masses from the final Planck and full-shape BOSS data

Cosmological parameters and neutrino masses from the final Planck and full-shape BOSS data

Assessing non-linear models for galaxy clustering – II. Model validation and forecasts for Stage IV surveys

Measuring neutrino masses with large-scale structure: Euclid forecast with controlled theoretical error

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