Searching for modified gravity with baryon oscillations: From SDSS to wide field multiobject spectroscopy (WFMOS) (original) (raw)
Related papers
arXiv: Cosmology and Nongalactic Astrophysics, 2020
Baryon Acoustic Oscillations (BAO) involves measuring the spatial distribution of galaxies to determine the growth rate of cosmic structure. We derive constraints on cosmological parameters from the complete BAO published measurements that include 333333333 data points in the effective redshift range 0.106leqzleq2.360.106 \leq z \leq 2.360.106leqzleq2.36. The Lambda\LambdaLambdaCDM model yields cosmological parameters as follows: Omegam=0.287pm0.004\Omega_m = 0.287 \pm 0.004Omegam=0.287pm0.004, OmegaLambda=0.712pm0.004\Omega_\Lambda = 0.712 \pm 0.004OmegaLambda=0.712pm0.004, H0=68.63pm0.32,km/sec/MpcH_0 = 68.63 \pm 0.32 \, km/sec/MpcH0=68.63pm0.32,km/sec/Mpc. The comoving distance from the BAO data is rd=148.4pm0.59Mpcr_d = 148.4 \pm 0.59 Mpcrd=148.4pm0.59Mpc. Combining the BAO data with the Cosmic Chronometers (CC) data and the Pantheon Type Ia supernova data sets increases the significance to around 5sigma5\sigma5sigma. Therefore, the cosmic acceleration, the dark energy effect and the Hubble constant can be constrained with high level of significance only from late-time data, independently of the Planck measurements.
Testing late-time cosmic acceleration with uncorrelated baryon acoustic oscillation dataset
Astronomy & Astrophysics
Baryon acoustic oscillations (BAO) involve measuring the spatial distribution of galaxies to determine the growth rate of cosmic structures. We derive constraints on cosmological parameters from 17 uncorrelated BAO measurements that were collected from 333 published data points in the effective redshift range 0.106 ≤ z ≤ 2.36. We test the correlation of the subset using a random covariance matrix. The Λ cold dark matter (ΛCDM) model fit yields the cosmological parameters Ωm = 0.261 ± 0.028 and ΩΛ = 0.733 ± 0.021. Combining the BAO data with the Cosmic Chronometers data, the Pantheon type Ia supernova, and the Hubble diagram of gamma-ray bursts and quasars, the Hubble constant yields 69.85 ± 1.27 km s−1 Mpc−1 and the sound horizon distance gives 146.1 ± 2.15 Mpc. Beyond the ΛCDM model we test ΩkCDM and wCDM. The spatial curvature is Ωk = −0.076 ± 0.012 and the dark energy equation of states is w = −0.989 ± 0.049. We perform the Akaike information criteria test to compare the three mo...
2011
We present measurements of the baryon acoustic peak at redshifts z= 0.44, 0.6 and 0.73 in the galaxy correlation function of the final data set of the WiggleZ Dark Energy Survey. We combine our correlation function with lower redshift measurements from the 6-degree Field Galaxy Survey and Sloan Digital Sky Survey, producing a stacked survey correlation function in which the statistical significance of the detection of the baryon acoustic peak is 4.9σ relative to a zero-baryon model with no peak. We fit cosmological models to this combined baryon acoustic oscillation (BAO) data set comprising six distance-redshift data points, and compare the results with similar cosmological fits to the latest compilation of supernovae (SNe) and cosmic microwave background (CMB) data. The BAO and SNe data sets produce consistent measurements of the equation-of-state w of dark energy, when separately combined with the CMB, providing a powerful check for systematic errors in either of these distance probes. Combining all data sets we determine w=-1.03 ± 0.08 for a flat universe, consistent with a cosmological constant model. Assuming dark energy is a cosmological constant and varying the spatial curvature, we find Ωk=-0.004 ± 0.006.
Testing General Relativity with the next generation of cosmological surveys
2019
The late-time acceleration expansion of the Universe is conceptually considered the great burdensome issue in theoretical physics (cosmological problem) dubbed dark energy (DE) problem. In general relativity (GR) framework view point, there are two ways to explain where this acceleration might originate from; this riddle might either emerge from some unknown dark energy models or general relativity is a mistake on cosmological scale and dark energy is insubstantial. Innovative efforts have been carried out to comprehend the origin of the cosmic acceleration, involving surveys such as baryon acoustic oscillations (BAOs), Type Ia supernovae, weak gravitational lensing and the abundance of galaxy clusters. The next generation of cosmological surveys including LSST, DES, eBOSS, DESI, PFS, SKA and WFIRST; are aimed to provide percent-level or higher measurement of history of expansion and growth of structure over a volume which is sizable fraction of the whole observable Universe, these ...
Observational probes of cosmic acceleration
Physics Reports, 2013
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 experimental efforts 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 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 test, and direct measurements of H_0. We present extensive forecasts for constraints on the dark energy equation of state and parameterized deviations from GR, achievable with Stage III and Stage IV experimental programs that incorporate supernovae, BAO, weak lensing, and CMB data. We also show the level of precision required for 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 with broad applications, and they continue the longstanding astronomical tradition of mapping the universe in ever greater detail over ever larger scales.
Dark Energy Constraints from Baryon Acoustic Oscillations
Astrophysical Journal, 2006
Baryon acoustic oscillations (BAO) in the galaxy power spectrum allows us to extract the scale of the comoving sound horizon at recombination, a cosmological standard ruler accurately determined by the cosmic microwave background anisotropy data. We examine various issues important in the use of BAO to probe dark energy. We find that assuming a flat universe, and priors on Omega_m, Omega_m h^2, and Omega_b h^2 as expected from the Planck mission, the constraints on dark energy parameters (w_0,w') scale much less steeply with survey area than (area)^{-1/2} for a given redshift range. The constraints on the dark energy density rho_X(z), however, do scale roughly with (area)^{-1/2} due to the strong correlation between H(z) and Omega_m (which reduces the effect of priors on Omega_m). Dark energy constraints from BAO are very sensitive to the assumed linear scale of matter clustering and the redshift accuracy of the survey. For a BAO survey with 0.5<= z <= 2, sigma(R)=0.4 (corresponding to k_{max}(z=0)=0.086 h Mpc^{-1}), and sigma_z/(1+z)=0.001, (sigma_{w_0},sigma_{w'})=(0.115, 0.183) and (0.069, 0.104) for survey areas of 1000 (deg)^2 and 10000 (deg)^2 respectively. We find that it is critical to minimize the bias in the scale estimates in order to derive reliable dark energy constraints. For a 1000 (10000) square degree BAO survey, a 1-sigma bias in ln H(z) leads to a 2-sigma (3-sigma) bias in w'. The bias in w' due to the same scale bias from ln D_A(z) is slightly smaller and opposite in sign. The results from this paper will be useful in assessing different proposed BAO surveys and guiding the design of optimal dark energy detection strategies.