scholarly journals The WiggleZ Dark Energy Survey: testing the cosmological model with baryon acoustic oscillations at z= 0.6

2011 ◽  
Vol 415 (3) ◽  
pp. 2892-2909 ◽  
Author(s):  
Chris Blake ◽  
Tamara Davis ◽  
Gregory B. Poole ◽  
David Parkinson ◽  
Sarah Brough ◽  
...  
Keyword(s):  
Dark Energy ◽  
Cosmological Model ◽  
Acoustic Oscillations ◽  
Dark Energy Survey ◽  
Baryon Acoustic Oscillations ◽  
Energy Survey

scholarly journals The WiggleZ Dark Energy Survey: mapping the distance-redshift relation with baryon acoustic oscillations

2011 ◽  
Vol 418 (3) ◽  
pp. 1707-1724 ◽  
Author(s):  
Chris Blake ◽  
Eyal A. Kazin ◽  
Florian Beutler ◽  
Tamara M. Davis ◽  
David Parkinson ◽  
...  
Keyword(s):  
Dark Energy ◽  
Acoustic Oscillations ◽  
Dark Energy Survey ◽  
Baryon Acoustic Oscillations ◽  
Energy Survey

scholarly journals Dark Energy Survey Year 1 results: measurement of the baryon acoustic oscillation scale in the distribution of galaxies to redshift 1

2018 ◽  
Vol 483 (4) ◽  
pp. 4866-4883 ◽  
Author(s):  
T M C Abbott ◽  
F B Abdalla ◽  
A Alarcon ◽  
S Allam ◽  
F Andrade-Oliveira ◽  
...  
Keyword(s):  
Dark Energy ◽  
Cold Dark Matter ◽  
Angular Diameter ◽  
Acoustic Oscillations ◽  
Distance Measurements ◽  
Angular Diameter Distance ◽  
Dark Energy Survey ◽  
Trade Offs ◽  
Physical Scale ◽  
Energy Survey

ABSTRACT We present angular diameter distance measurements obtained by locating the baryon acoustic oscillations (BAO) scale in the distribution of galaxies selected from the first year of Dark Energy Survey data. We consider a sample of over 1.3 million galaxies distributed over a footprint of 1336 deg2 with 0.6 < $z$photo < 1 and a typical redshift uncertainty of 0.03(1 + $z$). This sample was selected, as fully described in a companion paper, using a colour/magnitude selection that optimizes trade-offs between number density and redshift uncertainty. We investigate the BAO signal in the projected clustering using three conventions, the angular separation, the comoving transverse separation, and spherical harmonics. Further, we compare results obtained from template-based and machine-learning photometric redshift determinations. We use 1800 simulations that approximate our sample in order to produce covariance matrices and allow us to validate our distance scale measurement methodology. We measure the angular diameter distance, DA, at the effective redshift of our sample divided by the true physical scale of the BAO feature, rd. We obtain close to a 4 per cent distance measurement of DA($z$eff = 0.81)/rd = 10.75 ± 0.43. These results are consistent with the flat Λ cold dark matter concordance cosmological model supported by numerous other recent experimental results.

scholarly journals Towards habitable Earths with EUCLID and WFIRST

2010 ◽  
Vol 6 (S276) ◽  
pp. 349-353 ◽  
Author(s):  
Jean-Philippe Beaulieu ◽  
David P. Bennett ◽  
Eamonn Kerins ◽  
Matthew Penny
Keyword(s):  
Dark Energy ◽  
Extrasolar Planets ◽  
Space Mission ◽  
Acoustic Oscillations ◽  
Large Space ◽  
Dark Energy Survey ◽  
Survey Report ◽  
Type Ia ◽  
Exciting Development ◽  
Energy Survey

AbstractThe discovery of extrasolar planets is arguably the most exciting development in astrophysics during the past 15 years, rivalled only by the detection of dark energy. Two projects are now at the intersection of the two communities of exoplanet scientists and cosmologists: EUCLID, proposed as an ESA M-class mission; and WFIRST, the top-ranked large space mission for the next decade by the Astro 2010 Decadal Survey report. The missions are to have several important science programs: a dark energy survey using weak lensing, baryon acoustic oscillations, Type Ia supernova, a survey of exoplanetary architectures using microlensing, and different surveys. The WFIRST and EUCLID microlensing planet search programs will provide a statistical census of exoplanets with masses greater than the mass of Mars and orbital separations ranging from 0.5 AU outwards, including free-floating planets. This will include analogs of all Solar System planets except for Mercury, as well as most types of planets predicted by planet formation theories. In combination with Kepler's census of planets in shorter period orbits, EUCLID and WFIRST's planet search programs will provide a complete statistical census of the planets that populate our Galaxy. As of today, EUCLID is proposed to ESA as a M class mission (the result of the selection will be known in october 2011). We are presenting here preliminary results about the expected planet yields. WFIRST has just appointed a Science Definition Team.

scholarly journals Dark energy survey year 1 results: Constraining baryonic physics in the Universe

2021 ◽  
Vol 502 (4) ◽  
pp. 6010-6031
Author(s):  
Hung-Jin Huang ◽  
Tim Eifler ◽  
Rachel Mandelbaum ◽  
Gary M Bernstein ◽  
Anqi Chen ◽  
...  
Keyword(s):  
Dark Energy ◽  
Large Scale ◽  
Principal Component ◽  
External Information ◽  
Small Scale ◽  
Acoustic Oscillations ◽  
Dark Energy Survey ◽  
Theoretical Predictions ◽  
Hydrodynamical Simulations ◽  
Energy Survey

ABSTRACT Measurements of large-scale structure are interpreted using theoretical predictions for the matter distribution, including potential impacts of baryonic physics. We constrain the feedback strength of baryons jointly with cosmology using weak lensing and galaxy clustering observables (3 × 2pt) of Dark Energy Survey (DES) Year 1 data in combination with external information from baryon acoustic oscillations (BAO) and Planck cosmic microwave background polarization. Our baryon modelling is informed by a set of hydrodynamical simulations that span a variety of baryon scenarios; we span this space via a Principal Component (PC) analysis of the summary statistics extracted from these simulations. We show that at the level of DES Y1 constraining power, one PC is sufficient to describe the variation of baryonic effects in the observables, and the first PC amplitude (Q1) generally reflects the strength of baryon feedback. With the upper limit of Q1 prior being bound by the Illustris feedback scenarios, we reach $\sim 20{{\ \rm per\ cent}}$ improvement in the constraint of $S_8=\sigma _8(\Omega _{\rm m}/0.3)^{0.5}=0.788^{+0.018}_{-0.021}$ compared to the original DES 3 × 2pt analysis. This gain is driven by the inclusion of small-scale cosmic shear information down to 2.5 arcmin, which was excluded in previous DES analyses that did not model baryonic physics. We obtain $S_8=0.781^{+0.014}_{-0.015}$ for the combined DES Y1+Planck EE+BAO analysis with a non-informative Q1 prior. In terms of the baryon constraints, we measure $Q_1=1.14^{+2.20}_{-2.80}$ for DES Y1 only and $Q_1=1.42^{+1.63}_{-1.48}$ for DESY1+Planck EE+BAO, allowing us to exclude one of the most extreme AGN feedback hydrodynamical scenario at more than 2σ.

scholarly journals Dark energy survey internal consistency tests of the joint cosmological probes analysis with posterior predictive distributions

2021 ◽  
Vol 503 (2) ◽  
pp. 2688-2705
Author(s):  
C Doux ◽  
E Baxter ◽  
P Lemos ◽  
C Chang ◽  
A Alarcon ◽  
...  
Keyword(s):  
Dark Energy ◽  
Internal Consistency ◽  
Goodness Of Fit ◽  
Small Scale ◽  
P Value ◽  
Posterior Predictive Distribution ◽  
Data Set ◽  
Dark Energy Survey ◽  
Data Vector ◽  
Energy Survey

ABSTRACT Beyond ΛCDM, physics or systematic errors may cause subsets of a cosmological data set to appear inconsistent when analysed assuming ΛCDM. We present an application of internal consistency tests to measurements from the Dark Energy Survey Year 1 (DES Y1) joint probes analysis. Our analysis relies on computing the posterior predictive distribution (PPD) for these data under the assumption of ΛCDM. We find that the DES Y1 data have an acceptable goodness of fit to ΛCDM, with a probability of finding a worse fit by random chance of p = 0.046. Using numerical PPD tests, supplemented by graphical checks, we show that most of the data vector appears completely consistent with expectations, although we observe a small tension between large- and small-scale measurements. A small part (roughly 1.5 per cent) of the data vector shows an unusually large departure from expectations; excluding this part of the data has negligible impact on cosmological constraints, but does significantly improve the p-value to 0.10. The methodology developed here will be applied to test the consistency of DES Year 3 joint probes data sets.

scholarly journals KiDS+VIKING-450 and DES-Y1 combined: Cosmology with cosmic shear

2020 ◽  
Vol 638 ◽  
pp. L1 ◽  
Author(s):  
S. Joudaki ◽  
H. Hildebrandt ◽  
D. Traykova ◽  
N. E. Chisari ◽  
C. Heymans ◽  
...  
Keyword(s):  
Dark Energy ◽  
Cosmic Microwave Background ◽  
Gravitational Lensing ◽  
Error Model ◽  
Calibration Error ◽  
Microwave Background ◽  
Weak Gravitational Lensing ◽  
Dark Energy Survey ◽  
Cosmic Shear ◽  
Energy Survey

We present a combined tomographic weak gravitational lensing analysis of the Kilo Degree Survey (KV450) and the Dark Energy Survey (DES-Y1). We homogenize the analysis of these two public cosmic shear datasets by adopting consistent priors and modeling of nonlinear scales, and determine new redshift distributions for DES-Y1 based on deep public spectroscopic surveys. Adopting these revised redshifts results in a 0.8σ reduction in the DES-inferred value for S​8, which decreases to a 0.5σ reduction when including a systematic redshift calibration error model from mock DES data based on the MICE2 simulation. The combined KV450+DES-Y1 constraint on S8 = 0.762−0.024+0.025 is in tension with the Planck 2018 constraint from the cosmic microwave background at the level of 2.5σ. This result highlights the importance of developing methods to provide accurate redshift calibration for current and future weak-lensing surveys.

scholarly journals Dark Energy Survey Year 1 Results: Wide-field mass maps via forward fitting in harmonic space

2020 ◽  
Vol 493 (4) ◽  
pp. 5662-5679 ◽  
Author(s):  
B Mawdsley ◽  
D Bacon ◽  
C Chang ◽  
P Melchior ◽  
E Rozo ◽  
...  
Keyword(s):  
Dark Energy ◽  
Mapping Technique ◽  
Harmonic Space ◽  
Wide Field ◽  
Direct Inversion ◽  
Dark Energy Survey ◽  
Central Regions ◽  
Fitting In ◽  
Energy Survey ◽  
Good Agreement

ABSTRACT We present new wide-field weak lensing mass maps for the Year 1 Dark Energy Survey (DES) data, generated via a forward fitting approach. This method of producing maps does not impose any prior constraints on the mass distribution to be reconstructed. The technique is found to improve the map reconstruction on the edges of the field compared to the conventional Kaiser–Squires method, which applies a direct inversion on the data; our approach is in good agreement with the previous direct approach in the central regions of the footprint. The mapping technique is assessed and verified with tests on simulations; together with the Kaiser–Squires method, the technique is then applied to data from the DES Year 1 data and the differences between the two methods are compared. We also produce the first DES measurements of the convergence Minkowski functionals and compare them to those measured in simulations.

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