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A 6% measurement of the Hubble parameter at z∼0.45: direct evidence of the epoch of cosmic re-acceleration

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A 6% measurement of the Hubble parameter at z∼0.45 : direct evidence of the epoch of cosmic re-acceleration. / Moresco, Michele; Pozzetti, Lucia; Cimatti, Andrea; Jimenez, Raul; Maraston, Claudia; Verde, Licia; Thomas, Daniel; Citro, Annalisa; Tojeiro, Rita; Wilkinson, David.

In: Journal of Cosmology and Astroparticle Physics, Vol. 2016, No. May 2016, 014, 04.05.2016.

Research output: Contribution to journalArticle

Harvard

Moresco, M, Pozzetti, L, Cimatti, A, Jimenez, R, Maraston, C, Verde, L, Thomas, D, Citro, A, Tojeiro, R & Wilkinson, D 2016, 'A 6% measurement of the Hubble parameter at z∼0.45: direct evidence of the epoch of cosmic re-acceleration', Journal of Cosmology and Astroparticle Physics, vol. 2016, no. May 2016, 014. https://doi.org/10.1088/1475-7516/2016/05/014

APA

Moresco, M., Pozzetti, L., Cimatti, A., Jimenez, R., Maraston, C., Verde, L., Thomas, D., Citro, A., Tojeiro, R., & Wilkinson, D. (2016). A 6% measurement of the Hubble parameter at z∼0.45: direct evidence of the epoch of cosmic re-acceleration. Journal of Cosmology and Astroparticle Physics, 2016(May 2016), [014]. https://doi.org/10.1088/1475-7516/2016/05/014

Vancouver

Moresco M, Pozzetti L, Cimatti A, Jimenez R, Maraston C, Verde L et al. A 6% measurement of the Hubble parameter at z∼0.45: direct evidence of the epoch of cosmic re-acceleration. Journal of Cosmology and Astroparticle Physics. 2016 May 4;2016(May 2016). 014. https://doi.org/10.1088/1475-7516/2016/05/014

Author

Moresco, Michele ; Pozzetti, Lucia ; Cimatti, Andrea ; Jimenez, Raul ; Maraston, Claudia ; Verde, Licia ; Thomas, Daniel ; Citro, Annalisa ; Tojeiro, Rita ; Wilkinson, David. / A 6% measurement of the Hubble parameter at z∼0.45 : direct evidence of the epoch of cosmic re-acceleration. In: Journal of Cosmology and Astroparticle Physics. 2016 ; Vol. 2016, No. May 2016.

Bibtex

@article{faa5439913d94ce5a7c3a6b1b5d02461,
title = "A 6% measurement of the Hubble parameter at z∼0.45: direct evidence of the epoch of cosmic re-acceleration",
abstract = "Deriving the expansion history of the Universe is a major goal of modern cosmology. To date, the most accurate measurements have been obtained with Type Ia Supernovae (SNe) and Baryon Acoustic Oscillations (BAO), providing evidence for the existence of a transition epoch at which the expansion rate changes from decelerated to accelerated. However, these results have been obtained within the framework of specific cosmological models that must be implicitly or explicitly assumed in the measurement. It is therefore crucial to obtain measurements of the accelerated expansion of the Universe independently of assumptions on cosmological models. Here we exploit the unprecedented statistics provided by the Baryon Oscillation Spectroscopic Survey (BOSS, [1-3]) Data Release 9 to provide new constraints on the Hubble parameter H(z) using the cosmic chronometers approach. We extract a sample of more than 130000 of the most massive and passively evolving galaxies, obtaining five new cosmology-independent H(z) measurements in the redshift range 0.3 < z < 0.5, with an accuracy of ~11–16% incorporating both statistical and systematic errors. Once combined, these measurements yield a 6% accuracy constraint of H(z = 0.4293) = 91.8 ± 5.3 km/s/Mpc. The new data are crucial to provide the first cosmology-independent determination of the transition redshift at high statistical significance, measuring zt = 0.4 ± 0.1, and to significantly disfavor the null hypothesis of no transition between decelerated and accelerated expansion at 99.9% confidence level. This analysis highlights the wide potential of the cosmic chronometers approach: it permits to derive constraints on the expansion history of the Universe with results competitive with standard probes, and most importantly, being the estimates independent of the cosmological model, it can constrain cosmologies beyond—and including—the ΛCDM model.",
keywords = "astro-ph.CO, uploaded-in-3-months-elsewhere",
author = "Michele Moresco and Lucia Pozzetti and Andrea Cimatti and Raul Jimenez and Claudia Maraston and Licia Verde and Daniel Thomas and Annalisa Citro and Rita Tojeiro and David Wilkinson",
year = "2016",
month = may,
day = "4",
doi = "10.1088/1475-7516/2016/05/014",
language = "English",
volume = "2016",
journal = "Journal of Cosmology and Astroparticle Physics",
issn = "1475-7516",
publisher = "IOP Publishing",
number = "May 2016",

}

RIS

TY - JOUR

T1 - A 6% measurement of the Hubble parameter at z∼0.45

T2 - direct evidence of the epoch of cosmic re-acceleration

AU - Moresco, Michele

AU - Pozzetti, Lucia

AU - Cimatti, Andrea

AU - Jimenez, Raul

AU - Maraston, Claudia

AU - Verde, Licia

AU - Thomas, Daniel

AU - Citro, Annalisa

AU - Tojeiro, Rita

AU - Wilkinson, David

PY - 2016/5/4

Y1 - 2016/5/4

N2 - Deriving the expansion history of the Universe is a major goal of modern cosmology. To date, the most accurate measurements have been obtained with Type Ia Supernovae (SNe) and Baryon Acoustic Oscillations (BAO), providing evidence for the existence of a transition epoch at which the expansion rate changes from decelerated to accelerated. However, these results have been obtained within the framework of specific cosmological models that must be implicitly or explicitly assumed in the measurement. It is therefore crucial to obtain measurements of the accelerated expansion of the Universe independently of assumptions on cosmological models. Here we exploit the unprecedented statistics provided by the Baryon Oscillation Spectroscopic Survey (BOSS, [1-3]) Data Release 9 to provide new constraints on the Hubble parameter H(z) using the cosmic chronometers approach. We extract a sample of more than 130000 of the most massive and passively evolving galaxies, obtaining five new cosmology-independent H(z) measurements in the redshift range 0.3 < z < 0.5, with an accuracy of ~11–16% incorporating both statistical and systematic errors. Once combined, these measurements yield a 6% accuracy constraint of H(z = 0.4293) = 91.8 ± 5.3 km/s/Mpc. The new data are crucial to provide the first cosmology-independent determination of the transition redshift at high statistical significance, measuring zt = 0.4 ± 0.1, and to significantly disfavor the null hypothesis of no transition between decelerated and accelerated expansion at 99.9% confidence level. This analysis highlights the wide potential of the cosmic chronometers approach: it permits to derive constraints on the expansion history of the Universe with results competitive with standard probes, and most importantly, being the estimates independent of the cosmological model, it can constrain cosmologies beyond—and including—the ΛCDM model.

AB - Deriving the expansion history of the Universe is a major goal of modern cosmology. To date, the most accurate measurements have been obtained with Type Ia Supernovae (SNe) and Baryon Acoustic Oscillations (BAO), providing evidence for the existence of a transition epoch at which the expansion rate changes from decelerated to accelerated. However, these results have been obtained within the framework of specific cosmological models that must be implicitly or explicitly assumed in the measurement. It is therefore crucial to obtain measurements of the accelerated expansion of the Universe independently of assumptions on cosmological models. Here we exploit the unprecedented statistics provided by the Baryon Oscillation Spectroscopic Survey (BOSS, [1-3]) Data Release 9 to provide new constraints on the Hubble parameter H(z) using the cosmic chronometers approach. We extract a sample of more than 130000 of the most massive and passively evolving galaxies, obtaining five new cosmology-independent H(z) measurements in the redshift range 0.3 < z < 0.5, with an accuracy of ~11–16% incorporating both statistical and systematic errors. Once combined, these measurements yield a 6% accuracy constraint of H(z = 0.4293) = 91.8 ± 5.3 km/s/Mpc. The new data are crucial to provide the first cosmology-independent determination of the transition redshift at high statistical significance, measuring zt = 0.4 ± 0.1, and to significantly disfavor the null hypothesis of no transition between decelerated and accelerated expansion at 99.9% confidence level. This analysis highlights the wide potential of the cosmic chronometers approach: it permits to derive constraints on the expansion history of the Universe with results competitive with standard probes, and most importantly, being the estimates independent of the cosmological model, it can constrain cosmologies beyond—and including—the ΛCDM model.

KW - astro-ph.CO

KW - uploaded-in-3-months-elsewhere

UR - https://research-repository.st-andrews.ac.uk/handle/10023/9021

U2 - 10.1088/1475-7516/2016/05/014

DO - 10.1088/1475-7516/2016/05/014

M3 - Article

VL - 2016

JO - Journal of Cosmology and Astroparticle Physics

JF - Journal of Cosmology and Astroparticle Physics

SN - 1475-7516

IS - May 2016

M1 - 014

ER -

ID: 5270248