Motion of the acoustic peak in the correlation function

Smith, R. E.; Scoccimarro, Román; Sheth, Ravi K.

doi:10.1103/physrevd.77.043525

Cited by 149 publications

(207 citation statements)

References 72 publications

(100 reference statements)

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“…The optimal plan is then to fit that template to the data over a range of scales using the correct covariance matrix or likelihood. Some early works instead used non-parametric models for the acoustic peak, such as a Gaussian in configuration space or a damped sinusoid in Fourier space (Blake and Glazebrook, 2003), or simply identified the maximum of the correlation function (Guzik et al, 2007;Smith et al, 2008). We believe that, because the acoustic scale is predicted only in the context of an early universe model with parameters taken from fits to CMB data, there is no extra value in avoiding the linear-theory model predictions.…”

Section: Fitting To Datamentioning

confidence: 99%

Observational probes of cosmic acceleration

et al. 2013

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The accelerating expansion of the universe is the most surprising cosmological discovery in many decades, implying that the universe is dominated by some form of "dark energy" with exotic physical properties, or that Einstein's theory of gravity breaks down on cosmological scales. The profound implications of cosmic acceleration have inspired ambitious efforts to understand its origin, with experiments that aim to measure the history of expansion and growth of structure with percent-level precision or higher. We review in detail the four most well established methods for making such measurements: Type Ia supernovae, baryon acoustic oscillations (BAO), weak gravitational lensing, and the abundance of galaxy clusters. We pay particular attention to the systematic uncertainties in these techniques and to strategies for controlling them at the level needed to exploit "Stage IV" dark energy facilities such as BigBOSS, LSST, Euclid, and WFIRST. We briefly review a number of other approaches including redshift-space distortions, the Alcock-Paczynski effect, and direct measurements of the Hubble constant H 0 . We present extensive forecasts for constraints on the dark energy equation of state and parameterized deviations from General Relativity, achievable with Stage III and Stage IV experimental programs that incorporate supernovae, BAO, weak lensing, and cosmic microwave background data. We also show the level of precision required for clusters or other methods to provide constraints competitive with those of these fiducial programs. We emphasize the value of a balanced program that employs several of the most powerful methods in combination, both to cross-check systematic uncertainties and to take advantage of complementary information. Surveys to probe cosmic acceleration produce data sets that support a wide range of scientific investigations, and they continue the longstanding astronomical tradition of mapping the universe in ever greater detail over ever larger scales.

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Section: Fitting To Datamentioning

confidence: 99%

Observational probes of cosmic acceleration

et al. 2013

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“…A possible reason for this discrepancy could be that the 2-halo term in the redshift-space power spectrum only includes linear halo motions-nonlinear terms do contribute to this term (see [42,44,83]) and inclusion of these nonlinear corrections may help alleviate this problem. Another is that the concentration-mass relation, which is vital for getting the correct normalization of the halo density profiles, may not be sufficiently accurate.…”

Section: B Estimating the Power Spectrummentioning

confidence: 99%

Analytic model for the bispectrum of galaxies in redshift space

Smith

Sheth

2008

Phys. Rev. D

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We develop an analytic theory for the redshift space bispectrum of dark matter, haloes, and galaxies. This is done within the context of the halo model of structure formation, as this allows for the self consistent inclusion of linear and nonlinear redshift-space distortions and also for the nonlinearity of the halo bias. The model is applicable over a wide range of scales: on the largest scales the predictions reduce to those of the standard perturbation theory (PT); on smaller scales they are determined primarily by the nonlinear virial velocities of galaxies within haloes, and this gives rise to the U-shaped anisotropy in the reduced bispectrum-a finger print of the Finger-Of-God distortions. We then confront the predictions with measurements of the redshift-space bispectrum of dark matter from an ensemble of numerical simulations. On very large scales, k = 0.05h Mpc -1 , we find reasonably good agreement between our halo model, PT and the data, to within the errors. On smaller scales, k = 0.1h Mpc -1 , the measured bispectra differ from the PT at the level of ∼10%-20%, especially for colinear triangle configurations. The halo model predictions improve over PT, but are accurate to no better than 10%. On smaller scales k = 0.5-1.0h Mpc -1 , our model provides a significant improvement over PT, which breaks down. This implies that studies which use the lowest order PT to extract galaxy bias information are not robust on scales k ≳ 0.1h Mpc -1 . The analytic and simulation results also indicate that there is no observable scale for which the configuration dependence of the reduced bispectrum is constant-hierarchical models for the higher-order correlation functions in redshift space are unlikely to be useful. It is hoped that our model will facilitate extraction of information from large-scale structure surveys of the Universe, because different galaxy populations are naturally included into our description. Disciplines Physical Sciences and Mathematics | Physics CommentsSuggested Citation: R.E. Smith, R.K. We develop an analytic theory for the redshift space bispectrum of dark matter, haloes, and galaxies. This is done within the context of the halo model of structure formation, as this allows for the selfconsistent inclusion of linear and nonlinear redshift-space distortions and also for the nonlinearity of the halo bias. The model is applicable over a wide range of scales: on the largest scales the predictions reduce to those of the standard perturbation theory (PT); on smaller scales they are determined primarily by the nonlinear virial velocities of galaxies within haloes, and this gives rise to the U-shaped anisotropy in the reduced bispectrum-a finger print of the Finger-Of-God distortions. We then confront the predictions with measurements of the redshift-space bispectrum of dark matter from an ensemble of numerical simulations. On very large scales, k ¼ 0:05h Mpc À1 , we find reasonably good agreement between our halo model, PT and the data, to within the errors. On smaller scales, k ¼ 0:1h Mpc...

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“…In order to compare the observed galaxy clustering with that from underlying dark matter, one has to account for changes in the linear power spectrum (or correlation function) due to non-linear gravitational collapse and scale dependent bias of galaxies. Such effects introduce distortions on the linear power spectrum shape and can even shift the position of the acoustic peak of up to 3% (Smith et al 2008). Several models have been proposed to correct for these effects, usually supported by numerical simulations.…”

Section: Lss Analysis and Compressed Datamentioning

confidence: 99%

Constraints on CDM cosmology from galaxy power spectrum, CMB and SNIa evolution

Ferramacho¹,

Blanchard²,

Zolnierowski³

2009

A&A

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Aims. We examine the constraints that can be obtained on standard cold dark matter models from the most currently used data set: CMB anisotropies, type Ia supernovae and the SDSS luminous red galaxies. We also examine how these constraints are widened when the equation of state parameter w and the curvature parameter Ω k are left as free parameters. Finally, we investigate the impact on these constraints of a possible form of evolution in SNIa intrinsic luminosity. Methods. We obtained our results from MCMC analysis using the full likelihood of each data set. Results. For the ΛCDM model, our "vanilla" model, cosmological parameters are tightly constrained and consistent with current estimates from various methods. When the dark energy parameter w is free we find that the constraints remain mostly unchanged, i.e. changes are smaller than the 1 sigma uncertainties. Similarly, relaxing the assumption of a flat universe leads to nearly identical constraints on the dark energy density parameter of the universe Ω Λ , baryon density of the universe Ω b , the optical depth τ, the index of the power spectrum of primordial fluctuations n S , with most one sigma uncertainties better than 5%. More significant changes appear on other parameters: while preferred values are almost unchanged, uncertainties for the physical dark matter density Ω c h 2 , Hubble constant H 0 and σ 8 are typically twice as large. The constraint on the age of the Universe, which is very accurate for the vanilla model, is the most degraded. We found that different methodological approaches on large scale structure estimates lead to appreciable differences in preferred values and uncertainty widths. We found that possible evolution in SNIa intrinsic luminosity does not alter these constraints by much, except for w, for which the uncertainty is twice as large. At the same time, this possible evolution is severely constrained. Conclusions. We conclude that systematic uncertainties for some estimated quantities are similar or larger than statistical ones.

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Motion of the acoustic peak in the correlation function

Cited by 149 publications

References 72 publications

Observational probes of cosmic acceleration

Observational probes of cosmic acceleration

Analytic model for the bispectrum of galaxies in redshift space

Constraints on CDM cosmology from galaxy power spectrum, CMB and SNIa evolution

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