dc.contributor |
Universitat de Barcelona |
dc.contributor.author |
Cuesta, Antonio J. |
dc.contributor.author |
Gontcho, Satya Gontcho A. |
dc.contributor.author |
Miralda Escudé, Jordi |
dc.contributor.author |
BOSS Collaboration |
dc.date |
2016-06-21T09:07:52Z |
dc.date |
2016-06-21T09:07:52Z |
dc.date |
2015-12-14 |
dc.date |
2016-06-20T13:48:26Z |
dc.identifier.citation |
1550-7998 |
dc.identifier.citation |
642515 |
dc.identifier.uri |
http://hdl.handle.net/2445/99687 |
dc.format |
1 p. |
dc.format |
application/pdf |
dc.language.iso |
eng |
dc.publisher |
American Physical Society |
dc.relation |
Reproducció del document publicat a: http://dx.doi.org/10.1103/PhysRevD.92.123516 |
dc.relation |
Physical Review D, 2015, vol. 92, num. 12, p. 123516-1-123516-38 |
dc.relation |
http://dx.doi.org/10.1103/PhysRevD.92.123516 |
dc.rights |
(c) American Physical Society, 2015 |
dc.rights |
info:eu-repo/semantics/openAccess |
dc.subject |
Cosmologia |
dc.subject |
Espectroscòpia de microones |
dc.subject |
Cosmology |
dc.subject |
Microwave spectroscopy |
dc.title |
Cosmological implications of baryon acoustic oscillation measurements |
dc.type |
info:eu-repo/semantics/article |
dc.type |
info:eu-repo/semantics/publishedVersion |
dc.description.abstract |
We derive constraints on cosmological parameters and tests of dark energy models from the combination of baryon acoustic oscillation (BAO) measurements with cosmic microwave background (CMB) data and a recent reanalysis of Type Ia supernova (SN) data. In particular, we take advantage of high-precision BAO measurements from galaxy clustering and the Lyman-α forest (LyaF) in the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS). Treating the BAO scale as an uncalibrated standard ruler, BAO data alone yield a high confidence detection of dark energy; in combination with the CMB angular acoustic scale they further imply a nearly flat universe. Adding the CMB-calibrated physical scale of the sound horizon, the combination of BAO and SN data into an 'inverse distance ladder' yields a measurement of H0=67.3 ±1.1 km s-1 Mpc-1 , with 1.7% precision. This measurement assumes standard prerecombination physics but is insensitive to assumptions about dark energy or space curvature, so agreement with CMB-based estimates that assume a flat Λ CDM cosmology is an important corroboration of this minimal cosmological model. For constant dark energy (Λ ), our BAO +SN +CMB combination yields matter density Ωm=0.301 ±0.008 and curvature Ωk=-0.003 ±0.003 . When we allow more general forms of evolving dark energy, the BAO +SN +CMB parameter constraints are always consistent with flat Λ CDM values at ≈1 σ . While the overall χ2 of model fits is satisfactory, the LyaF BAO measurements are in moderate (2 - 2.5 σ ) tension with model predictions. Models with early dark energy that tracks the dominant energy component at high redshift remain consistent with our expansion history constraints, and they yield a higher H0 and lower matter clustering amplitude, improving agreement with some low redshift observations. Expansion history alone yields an upper limit on the summed mass of neutrino species, ∑mν<0.56 eV (95% confidence), improving to ∑mν<0.25 eV if we include the lensing signal in the Planck CMB power spectrum. In a flat Λ CDM model that allows extra relativistic species, our data combination yields Neff=3.43 ±0.26 ; while the LyaF BAO data prefer higher Neff when excluding galaxy BAO, the galaxy BAO alone favor Neff≈3 . When structure growth is extrapolated forward from the CMB to low redshift, standard dark energy models constrained by our data predict a level of matter clustering that is high compared to most, but not all, observational estimates. |