53 research outputs found

    Anisotropic galaxy clustering measurements in Fourier space and cosmological implications from the BOSS DR12 sample

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    Moderne Rotverschiebungs-Galaxiendurchmusterungen können mittels Mehrfach-Faser-Spektroskopie große Bereiche des Himmels abdecken. Dank der immer grĂ¶ĂŸer werdenden DatensĂ€tze hat sich die Analyse der großskaligen Galaxienverteilung im Universum zu einer unschĂ€tzbaren Wissensquelle fĂŒr die Kosmologie entwickelt. Zusammen mit den Beobachtungen des kosmischen Mikrowellenhintergrunds (MWH) und Entfernungsbestimmungen anhand von großen Typ-Ia-Supernova-DatensĂ€tzen (SN) bilden die Galaxiendurchmusterungen ausschlaggebende Indikatoren fĂŒr die Korrektheit der Paradigmen des kosmologischen Weltbilds, des ΛCDM-Modells. Die Auswertung der Galaxienverteilung erlaubt mit Hilfe des Standardlineals, das durch die Baryonisch-akustischen Oszillationen gegeben ist, Entfernungsmessungen von ungesehener PrĂ€zision. Dies gewĂ€hrt Einblick in die zugrundeliegende physikalische Natur der Dunklen Energie (DE), welche fĂŒr die Beschleunigung der Ausdehung unseres Universums verantwortlich gemacht wird, indem die zeitliche Entwicklung der DE-Zustandsgleichung einge- schrĂ€nkt werden kann. Zudem kann aus dem Signal der Verzerrungen im Rotverschiebungsraum die Wachstumsrate von kosmologischer Struktur bestimmt werden. Dies stellt einen Test der RelativitĂ€tstheorie dar, weil mögliche erweiterte Gravitationstheorien abweichende Wachstumsraten vorhersagen können. Die abgeschlossenen Rotverschiebungsmessungen des ‘Baryon Acoustic Oscillation Survey’-Programms (kurz BOSS) brachten einen Galaxienkatalog hervor, der ein bisher unerreichtes Volumen abdeckt. In dieser Dissertation wird die kosmologische Information, die im rĂ€umlichen Leistungsdichtespektrum (LDS) der Rotverschiebungsraum-Galaxienverteilung des BOSS-Katalogs enthalten ist, genutzt, um den Parameterraum des ΛCDM-Modells und der wichtigsten möglichen Erweiterungen einzuschrĂ€nken. Vorherige Analysen des anisotropen Galaxien-LDS waren auf die Messung der Multipolzerlegung beschrĂ€nkt. FĂŒr die hier prĂ€sentierte Analyse wurde das Konzept der sogenannten ‘Clustering Wedges’ auf den Fourierraum ĂŒbertragen, um einen komplementĂ€ren Ansatz zur Vermessung des anisotropen LDS zu verfolgen. Dazu wird der varianzoptimierte SchĂ€tzer fĂŒr LDS-Wedges definiert und an die Galaxiengewichtung, die unvermeidbare Beobachtungsfehler im BOSS-Katalog behebt, angepasst. Zudem wird auch der Formalismus zur Beschreibung der Fensterfunktion auf die Wedges erweitert. Das verwendete Modell fĂŒr das anistrope Galaxien-LDS ist auf neuartigen AnsĂ€tzen zur Modellierung der nichtlinearen Gravitationsdynamik und der Verzerrungen im Rotverschiebungsraum aufgebaut, welche die Genauigkeit der Modellvorhersagen speziell im Übergang in den nichtlinearen Bereich signifikant verbessern. Daher kann das LDS bis zu kleineren Skalen als in vorherigen Analysen ausgewertet werden, wodurch engere EinschrĂ€nkungen des kosmologischen Parameterraums erreicht werden. Die Modellierung wurde mit Hilfe von synthetischen Katalogen, die auf großvolumigen Mehrkörpersimulationen basieren, verifiziert. Dazu ist eine theoretische Vorhersage der Kovarianzmatrix der anisotropischen Vermessung der Galaxienverteilung nötig, wofĂŒr ein Gaußsches Vorhersagemodell entwickelt wurde. Dieses ist neben den Wedges auch fĂŒr die komplementĂ€re Multipolzerlegung sowohl des LDS als auch dessen Fouriertransformierten, der Zwei-Punkt-Korrelationsfunktion, anwendbar. Die LDS-Analyse anhand von Clustering Wedges, wie in dieser Arbeit prĂ€sentiert, ist Teil der kombinierten Analyse des finalen Galaxienkatalogs im Rahmen der BOSS-Kollaboration. Unter Verwendung von zwei sich nicht ĂŒberschneidenden Rotverschiebungsbereichen wird die Winkeldurchmesserentfernung zu D_M(z_eff = 0.38) (rfid_d / r_d) = 1525 +-24 h^-1 Mpc und D_M(z_eff = 0.61) (rfid_d / r_d) = 2281 +42 -43 h^-1 Mpc bestimmt. Weiterhin wird der Hubbleparameter zu H(z_eff = 0.38) (r_d / rfid_d) = 81.2 +2.2 −2.3 km s^-1 Mpc^-1 und H(z_eff = 0.61) (r_d / rfid_d) = 94.9 +-2.5 km s^-1 Mpc^-1 vermessen (alle hier angegebenen Bereiche entsprechen einem Konfidenzintervall von 68%). Die Wachstumsrate wird eingeschrĂ€nkt auf fσ_8 (z_eff = 0.38) = 0.498 +0.044 -0.045 und fσ_8 (z_eff = 0.61) = 0.409 +-0.040. Zusammen mit den Ergebnissen der komplementĂ€ren Methoden, die innerhalb der BOSS-Kollaboration zur Clustering-Analyse des finalen Galaxienkatalogs eingesetzt werden, werden diese Resultate zu einem abschließenden Konsensergebnis zusammengefasst. Nur mit den Clustering-Weges-Messungen im Fourierraum, kombiniert mit MWH- und SN-Daten, kann der Materiedichteparameter auf Ω_M = 0.311 +0.009 -0.010 und die Hubble-Konstante auf H_0 = 67.6 +0.7 -0.6 km s^-1 Mpc^−1 unter Annahme des ΛCDM-Modells eingeschrĂ€nken werden. Wird ein Nichtstandard-Modell fĂŒr DE angenommen, so ergibt sich ein DE-Zustandsgleichungsparameter von w_DE = 1.019 +0.048 -0.039. Modifikationen der Wachstumsrate, parametrisiert durch f(z) = [Ω_M(z)]^Îł, werden auf Îł = 0.52 +- 0.10 eingeschrĂ€nkt. Diese beiden Messungen sind in perfekter Übereinstimmung mit den Vorhersagen des ΛCDM-Modells, ebenso wie weitere Ergebnisse, die sich unter der Annahme eines noch großzĂŒgigeren DE-Modells (welches eine zeitliche Entwicklung von w_DE erlaubt) ergeben. Daher wird das ΛCDM-Modell durch die hier beschriebene Analyse weiter gefestigt. Die Summe der Neutrinomassen wird zu sum(m_Îœ) < 0.143 eV bestimmt. Dieses obere Limit befindet sich nicht weit entfernt von der unteren Schranke, die sich aus Teilchenphysik-Experimenten ergibt. Somit ist zu erwarten, dass die kosmologische Signatur, die massebehaftete Neutrinos in der großskaligen Struktur des Universums hinterlassen, in naher Zukunft detektiert werden kann.Galaxy surveys cover a large fraction of the celestial sphere using modern multi-fibre spectrographs. Thanks to ever increasing datasets, the analysis of the large-scale structure (LSS) of the Universe has become a prolific source of cosmological information. Together with the observations of the cosmic microwave background (CMB) and samples of supernova (SN) of type Ia, they helped to establish the standard cosmological paradigm, the ΛCDM model. From the analysis of redshift-space galaxy clustering, the expansion history of the Universe can be inferred using the feature of Baryon Acoustic Oscillations (BAO) as a standard ruler to measure cosmic distances. The growth rate of cosmic structure can also be determined using redshift-space distortions (RSD). These measurements provide insight into competing alternatives of the ΛCDM model. The nature of the Dark Energy (DE), a strange component that is believed to be responsible for the current phase of accelerating expansion of the Universe, can be unravelled from BAO measurements of the late-time expansion. Modified theories of gravity can be constrained from the growth rate extracted from RSD, which can deviate from the prediction of general relativity. The redshift measurements of the Baryon Acoustic Oscillation Survey (BOSS) program that was completed in 2014 yielded a galaxy sample that covers an unprecedented volume. In this thesis, the standard model and its most important extensions are analysed using the cosmological information in the full-shape of the redshift-space two-point statistics measured from the final BOSS galaxy sample. So far, anisotropic clustering analyses in Fourier space relied on power spectrum multipole measurements. For this work, the concept of clustering wedges was extended to Fourier space to establish a complementary approach to measure clustering anisotropies: we introduce the optimal-variance estimator for clustering wedges, which is designed to account for systematic weights that correct the observational incompleteness of the BOSS sample, and also develop the window function formalism for the wedges. Our modelling of the anisotropic galaxy clustering is based on novel approaches for the description of non-linear gravitational dynamics and redshift-space distortions. This improved modelling allows us to include smaller scales in our full-shape fits than in previous BAO+RSD studies, resulting in tighter cosmological constraints. The galaxy clustering model is verified using synthetic catalogues based on large-volume N -body simulations. As this test requires a theoretical description for the anisotropic clustering covariance matrix, a Gaussian formalism was developed for that purpose. As a side project, this formalism is extended to describe clustering wedges and multipoles in Fourier and configuration space. The Fourier-space clustering measurements presented in this thesis are part of the joint analysis of the final BOSS sample. Using two non-overlapping redshift bins, we measure an angular diameter distance of D_M(z_eff = 0.38) (rfid_d / r_d) = 1525 +-24 h^-1 Mpc and D_M(z_eff = 0.61) (rfid_d / r_d) = 2281 +42 -43 h^-1 Mpc, as well as a Hubble parameter of H(z_eff = 0.38) (r_d / rfid_d) = 81.2 +2.2 −2.3 km s^-1 Mpc^-1 and H(z_eff = 0.61) (r_d / rfid_d) = 94.9 +-2.5 km s^-1 Mpc^-1 (all limits correspond to the statistical error of a confidence level of 68%). The growth rate is constrained to fσ_8 (z_eff = 0.38) = 0.498 +0.044 -0.045 und fσ_8 (z_eff = 0.61) = 0.409 +-0.040. These measurements will be combined with the complementary results from other galaxy clustering methods in configuration and Fourier space in order to determine the final BOSS consensus measurements. From our analysis alone, in combination with CMB and SN Ia data, we obtain a matter density parameter of Ω_M = 0.311 +0.009 -0.010 and a local Hubble parameter of H_0 = 67.6 +0.7 -0.6 km s^-1 Mpc^−1 assuming a ΛCDM cosmology. Allowing for a non-standard DE model, we find an equation-of-state parameter of w_DE = 1.019 +0.048 -0.039. Modifications of the growth rate, parametrized as f(z) = [Ω_M(z)]^Îł, are constrained to Îł = 0.52 ± 0.10. These two results, along with those obtained using a more general DE model to identify a time-evolution of w_DE, are in perfect agreement with the ΛCDM predictions. Thus, the standard paradigm is further consolidated by our analysis. The sum of neutrino masses is found to be sum(m_Îœ) < 0.143 eV. As this limit is close to the lower bound from particle physics, a detection of the cosmological signature of massive neutrinos from LSS analyses can be expected in the near future.Deutsche Übersetzung des Titels: Anisotrope Messungen der Galaxien-HĂ€ufungsverteilung im Fourierraum und kosmologische Implikationen des BOSS-DR12-Galaxiensample

    Anisotropic galaxy clustering measurements in Fourier space and cosmological implications from the BOSS DR12 sample

    Get PDF
    Moderne Rotverschiebungs-Galaxiendurchmusterungen können mittels Mehrfach-Faser-Spektroskopie große Bereiche des Himmels abdecken. Dank der immer grĂ¶ĂŸer werdenden DatensĂ€tze hat sich die Analyse der großskaligen Galaxienverteilung im Universum zu einer unschĂ€tzbaren Wissensquelle fĂŒr die Kosmologie entwickelt. Zusammen mit den Beobachtungen des kosmischen Mikrowellenhintergrunds (MWH) und Entfernungsbestimmungen anhand von großen Typ-Ia-Supernova-DatensĂ€tzen (SN) bilden die Galaxiendurchmusterungen ausschlaggebende Indikatoren fĂŒr die Korrektheit der Paradigmen des kosmologischen Weltbilds, des ΛCDM-Modells. Die Auswertung der Galaxienverteilung erlaubt mit Hilfe des Standardlineals, das durch die Baryonisch-akustischen Oszillationen gegeben ist, Entfernungsmessungen von ungesehener PrĂ€zision. Dies gewĂ€hrt Einblick in die zugrundeliegende physikalische Natur der Dunklen Energie (DE), welche fĂŒr die Beschleunigung der Ausdehung unseres Universums verantwortlich gemacht wird, indem die zeitliche Entwicklung der DE-Zustandsgleichung einge- schrĂ€nkt werden kann. Zudem kann aus dem Signal der Verzerrungen im Rotverschiebungsraum die Wachstumsrate von kosmologischer Struktur bestimmt werden. Dies stellt einen Test der RelativitĂ€tstheorie dar, weil mögliche erweiterte Gravitationstheorien abweichende Wachstumsraten vorhersagen können. Die abgeschlossenen Rotverschiebungsmessungen des ‘Baryon Acoustic Oscillation Survey’-Programms (kurz BOSS) brachten einen Galaxienkatalog hervor, der ein bisher unerreichtes Volumen abdeckt. In dieser Dissertation wird die kosmologische Information, die im rĂ€umlichen Leistungsdichtespektrum (LDS) der Rotverschiebungsraum-Galaxienverteilung des BOSS-Katalogs enthalten ist, genutzt, um den Parameterraum des ΛCDM-Modells und der wichtigsten möglichen Erweiterungen einzuschrĂ€nken. Vorherige Analysen des anisotropen Galaxien-LDS waren auf die Messung der Multipolzerlegung beschrĂ€nkt. FĂŒr die hier prĂ€sentierte Analyse wurde das Konzept der sogenannten ‘Clustering Wedges’ auf den Fourierraum ĂŒbertragen, um einen komplementĂ€ren Ansatz zur Vermessung des anisotropen LDS zu verfolgen. Dazu wird der varianzoptimierte SchĂ€tzer fĂŒr LDS-Wedges definiert und an die Galaxiengewichtung, die unvermeidbare Beobachtungsfehler im BOSS-Katalog behebt, angepasst. Zudem wird auch der Formalismus zur Beschreibung der Fensterfunktion auf die Wedges erweitert. Das verwendete Modell fĂŒr das anistrope Galaxien-LDS ist auf neuartigen AnsĂ€tzen zur Modellierung der nichtlinearen Gravitationsdynamik und der Verzerrungen im Rotverschiebungsraum aufgebaut, welche die Genauigkeit der Modellvorhersagen speziell im Übergang in den nichtlinearen Bereich signifikant verbessern. Daher kann das LDS bis zu kleineren Skalen als in vorherigen Analysen ausgewertet werden, wodurch engere EinschrĂ€nkungen des kosmologischen Parameterraums erreicht werden. Die Modellierung wurde mit Hilfe von synthetischen Katalogen, die auf großvolumigen Mehrkörpersimulationen basieren, verifiziert. Dazu ist eine theoretische Vorhersage der Kovarianzmatrix der anisotropischen Vermessung der Galaxienverteilung nötig, wofĂŒr ein Gaußsches Vorhersagemodell entwickelt wurde. Dieses ist neben den Wedges auch fĂŒr die komplementĂ€re Multipolzerlegung sowohl des LDS als auch dessen Fouriertransformierten, der Zwei-Punkt-Korrelationsfunktion, anwendbar. Die LDS-Analyse anhand von Clustering Wedges, wie in dieser Arbeit prĂ€sentiert, ist Teil der kombinierten Analyse des finalen Galaxienkatalogs im Rahmen der BOSS-Kollaboration. Unter Verwendung von zwei sich nicht ĂŒberschneidenden Rotverschiebungsbereichen wird die Winkeldurchmesserentfernung zu D_M(z_eff = 0.38) (rfid_d / r_d) = 1525 +-24 h^-1 Mpc und D_M(z_eff = 0.61) (rfid_d / r_d) = 2281 +42 -43 h^-1 Mpc bestimmt. Weiterhin wird der Hubbleparameter zu H(z_eff = 0.38) (r_d / rfid_d) = 81.2 +2.2 −2.3 km s^-1 Mpc^-1 und H(z_eff = 0.61) (r_d / rfid_d) = 94.9 +-2.5 km s^-1 Mpc^-1 vermessen (alle hier angegebenen Bereiche entsprechen einem Konfidenzintervall von 68%). Die Wachstumsrate wird eingeschrĂ€nkt auf fσ_8 (z_eff = 0.38) = 0.498 +0.044 -0.045 und fσ_8 (z_eff = 0.61) = 0.409 +-0.040. Zusammen mit den Ergebnissen der komplementĂ€ren Methoden, die innerhalb der BOSS-Kollaboration zur Clustering-Analyse des finalen Galaxienkatalogs eingesetzt werden, werden diese Resultate zu einem abschließenden Konsensergebnis zusammengefasst. Nur mit den Clustering-Weges-Messungen im Fourierraum, kombiniert mit MWH- und SN-Daten, kann der Materiedichteparameter auf Ω_M = 0.311 +0.009 -0.010 und die Hubble-Konstante auf H_0 = 67.6 +0.7 -0.6 km s^-1 Mpc^−1 unter Annahme des ΛCDM-Modells eingeschrĂ€nken werden. Wird ein Nichtstandard-Modell fĂŒr DE angenommen, so ergibt sich ein DE-Zustandsgleichungsparameter von w_DE = 1.019 +0.048 -0.039. Modifikationen der Wachstumsrate, parametrisiert durch f(z) = [Ω_M(z)]^Îł, werden auf Îł = 0.52 +- 0.10 eingeschrĂ€nkt. Diese beiden Messungen sind in perfekter Übereinstimmung mit den Vorhersagen des ΛCDM-Modells, ebenso wie weitere Ergebnisse, die sich unter der Annahme eines noch großzĂŒgigeren DE-Modells (welches eine zeitliche Entwicklung von w_DE erlaubt) ergeben. Daher wird das ΛCDM-Modell durch die hier beschriebene Analyse weiter gefestigt. Die Summe der Neutrinomassen wird zu sum(m_Îœ) < 0.143 eV bestimmt. Dieses obere Limit befindet sich nicht weit entfernt von der unteren Schranke, die sich aus Teilchenphysik-Experimenten ergibt. Somit ist zu erwarten, dass die kosmologische Signatur, die massebehaftete Neutrinos in der großskaligen Struktur des Universums hinterlassen, in naher Zukunft detektiert werden kann.Galaxy surveys cover a large fraction of the celestial sphere using modern multi-fibre spectrographs. Thanks to ever increasing datasets, the analysis of the large-scale structure (LSS) of the Universe has become a prolific source of cosmological information. Together with the observations of the cosmic microwave background (CMB) and samples of supernova (SN) of type Ia, they helped to establish the standard cosmological paradigm, the ΛCDM model. From the analysis of redshift-space galaxy clustering, the expansion history of the Universe can be inferred using the feature of Baryon Acoustic Oscillations (BAO) as a standard ruler to measure cosmic distances. The growth rate of cosmic structure can also be determined using redshift-space distortions (RSD). These measurements provide insight into competing alternatives of the ΛCDM model. The nature of the Dark Energy (DE), a strange component that is believed to be responsible for the current phase of accelerating expansion of the Universe, can be unravelled from BAO measurements of the late-time expansion. Modified theories of gravity can be constrained from the growth rate extracted from RSD, which can deviate from the prediction of general relativity. The redshift measurements of the Baryon Acoustic Oscillation Survey (BOSS) program that was completed in 2014 yielded a galaxy sample that covers an unprecedented volume. In this thesis, the standard model and its most important extensions are analysed using the cosmological information in the full-shape of the redshift-space two-point statistics measured from the final BOSS galaxy sample. So far, anisotropic clustering analyses in Fourier space relied on power spectrum multipole measurements. For this work, the concept of clustering wedges was extended to Fourier space to establish a complementary approach to measure clustering anisotropies: we introduce the optimal-variance estimator for clustering wedges, which is designed to account for systematic weights that correct the observational incompleteness of the BOSS sample, and also develop the window function formalism for the wedges. Our modelling of the anisotropic galaxy clustering is based on novel approaches for the description of non-linear gravitational dynamics and redshift-space distortions. This improved modelling allows us to include smaller scales in our full-shape fits than in previous BAO+RSD studies, resulting in tighter cosmological constraints. The galaxy clustering model is verified using synthetic catalogues based on large-volume N -body simulations. As this test requires a theoretical description for the anisotropic clustering covariance matrix, a Gaussian formalism was developed for that purpose. As a side project, this formalism is extended to describe clustering wedges and multipoles in Fourier and configuration space. The Fourier-space clustering measurements presented in this thesis are part of the joint analysis of the final BOSS sample. Using two non-overlapping redshift bins, we measure an angular diameter distance of D_M(z_eff = 0.38) (rfid_d / r_d) = 1525 +-24 h^-1 Mpc and D_M(z_eff = 0.61) (rfid_d / r_d) = 2281 +42 -43 h^-1 Mpc, as well as a Hubble parameter of H(z_eff = 0.38) (r_d / rfid_d) = 81.2 +2.2 −2.3 km s^-1 Mpc^-1 and H(z_eff = 0.61) (r_d / rfid_d) = 94.9 +-2.5 km s^-1 Mpc^-1 (all limits correspond to the statistical error of a confidence level of 68%). The growth rate is constrained to fσ_8 (z_eff = 0.38) = 0.498 +0.044 -0.045 und fσ_8 (z_eff = 0.61) = 0.409 +-0.040. These measurements will be combined with the complementary results from other galaxy clustering methods in configuration and Fourier space in order to determine the final BOSS consensus measurements. From our analysis alone, in combination with CMB and SN Ia data, we obtain a matter density parameter of Ω_M = 0.311 +0.009 -0.010 and a local Hubble parameter of H_0 = 67.6 +0.7 -0.6 km s^-1 Mpc^−1 assuming a ΛCDM cosmology. Allowing for a non-standard DE model, we find an equation-of-state parameter of w_DE = 1.019 +0.048 -0.039. Modifications of the growth rate, parametrized as f(z) = [Ω_M(z)]^Îł, are constrained to Îł = 0.52 ± 0.10. These two results, along with those obtained using a more general DE model to identify a time-evolution of w_DE, are in perfect agreement with the ΛCDM predictions. Thus, the standard paradigm is further consolidated by our analysis. The sum of neutrino masses is found to be sum(m_Îœ) < 0.143 eV. As this limit is close to the lower bound from particle physics, a detection of the cosmological signature of massive neutrinos from LSS analyses can be expected in the near future.Deutsche Übersetzung des Titels: Anisotrope Messungen der Galaxien-HĂ€ufungsverteilung im Fourierraum und kosmologische Implikationen des BOSS-DR12-Galaxiensample

    Gaussian covariance matrices for anisotropic galaxy clustering measurements

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    Measurements of the redshift-space galaxy clustering have been a prolific source of cosmological information in recent years. Accurate covariance estimates are an essential step for the validation of galaxy clustering models of the redshift-space two-point statistics. Usually, only a limited set of accurate N-body simulations is available. Thus, assessing the data covariance is not possible or only leads to a noisy estimate. Further, relying on simulated realisations of the survey data means that tests of the cosmology dependence of the covariance are expensive. With these points in mind, this work presents a simple theoretical model for the linear covariance of anisotropic galaxy clustering observations with synthetic catalogues. Considering the Legendre moments (`multipoles') of the two-point statistics and projections into wide bins of the line-of-sight parameter (`clustering wedges'), we describe the modelling of the covariance for these anisotropic clustering measurements for galaxy samples with a trivial geometry in the case of a Gaussian approximation of the clustering likelihood. As main result of this paper, we give the explicit formulae for Fourier and configuration space covariance matrices. To validate our model, we create synthetic HOD galaxy catalogues by populating the haloes of an ensemble of large-volume N-body simulations. Using linear and non-linear input power spectra, we find very good agreement between the model predictions and the measurements on the synthetic catalogues in the quasi-linear regime.Comment: 17 pages, 16 figures, 3 tables; modified to match version accepted by MNRA

    The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: Angular clustering tomography and its cosmological implications

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    We investigate the cosmological implications of studying galaxy clustering using a tomographic approach applied to the final BOSS DR12 galaxy sample, including both auto- and cross-correlation functions between redshift shells. We model the signal of the full shape of the angular correlation function, ω(Ξ)\omega(\theta), in redshift bins using state-of-the-art modelling of non-linearities, bias and redshift-space distortions. We present results on the redshift evolution of the linear bias of BOSS galaxies, which cannot be obtained with traditional methods for galaxy-clustering analysis. We also obtain constraints on cosmological parameters, combining this tomographic analysis with measurements of the cosmic microwave background (CMB) and type Ia supernova (SNIa). We explore a number of cosmological models, including the standard Λ\LambdaCDM model and its most interesting extensions, such as deviations from w_\rm{DE} = -1, non-minimal neutrino masses, spatial curvature and deviations from general relativity using the growth-index Îł\gamma parametrisation. These results are, in general, comparable to the most precise present-day constraints on cosmological parameters, and show very good agreement with the standard model. In particular, combining CMB, ω(Ξ)\omega(\theta) and SNIa, we find a value of w_\rm{DE} consistent with −1-1 to a precision better than 5\% when it is assumed to be constant in time, and better than 6\% when we also allow for a spatially-curved Universe.Comment: 21 pages, 18 figures, accepted for publication MNRAS. The data used in this analysis is publicly available at https://sdss3.org/science/boss_publications.ph

    The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: Mock galaxy catalogues for the BOSS Final Data Release

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    We reproduce the galaxy clustering catalogue from the SDSS-III Baryon Oscillation Spectroscopic Survey Final Data Release (BOSS DR11 and DR12) with high fidelity on all relevant scales in order to allow a robust analysis of baryon acoustic oscillations and redshift space distortions. We have generated (6000) 12 288 MultiDark PATCHY BOSS (DR11) DR12 light cones corresponding to an effective volume of ~ 192 000 [h-1 Gpc]3 (the largest ever simulated volume), including cosmic evolution in the redshift range from 0.15 to 0.75. The mocks have been calibrated using a reference galaxy catalogue based on the halo abundance matching modelling of the BOSS DR11 and DR12 galaxy clustering data and on the data themselves. The production follows three steps. First, we apply the PATCHY code to generate a dark matter field and an object distribution including non-linear stochastic galaxy bias. Secondly, we run the halo/stellar distribution reconstruction HADRON code to assign masses to the various objects. This step uses the mass distribution as a function of local density and non-local indicators (i.e. tidal field tensor eigenvalues and relative halo exclusion separation for massive objects) from the reference simulation applied to the corresponding patchy dark matter and galaxy distribution. Finally, we apply the SUGAR code to build the light cones. The resulting MultiDarkPATCHY mock light cones reproduce the number density, selection function, survey geometry, and in general within 1s, for arbitrary stellar mass bins, the power spectrum up to k = 0.3 h Mpc-1, the two-point correlation functions down to a few Mpc scales, and the three-point statistics of the BOSS DR11 and DR12 galaxy samples.Fil: Kitaura, Francisco-Shu. Leibniz-Institut fĂŒr Astrophysik Potsdam; AlemaniaFil: Rodriguez Torres, Sergio A.. Universidad AutĂłnoma de Madrid; España. Consejo Superior de Investigaciones CientĂ­ficas; EspañaFil: Chuang, Chia Hsun. Universidad AutĂłnoma de Madrid; España. Consejo Superior de Investigaciones CientĂ­ficas; EspañaFil: Zhao, Cheng. Tsinghua University; ChinaFil: Prada, Francisco. Consejo Superior de Investigaciones CientĂ­ficas; España. Universidad AutĂłnoma de Madrid; EspañaFil: Gil MarĂ­n, HĂ©ctor. University of Portsmouth; Reino UnidoFil: Guo, Hong. State University of Utah; Estados Unidos. Shanghai Astronomical Observatory; ChinaFil: Yepes, Gustavo. Universidad AutĂłnoma de Madrid. Facultad de Ciencias; EspañaFil: Klypin, Anatoly. Universidad AutĂłnoma de Madrid; España. Consejo Superior de Investigaciones CientĂ­ficas; España. New Mexico State University; Estados UnidosFil: Scoccola, Claudia Graciela. Universidad AutĂłnoma de Madrid; España. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata; Argentina. Instituto de Astrof{isica de Canarias; España. Universidad de La Laguna; EspañaFil: Tinker, Jeremy. University of New York; Estados UnidosFil: McBride, Cameron. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Reid, Beth. Lawrence Berkeley National Laboratory; Estados Unidos. University of California at Berkeley; Estados UnidosFil: SĂĄnchez, Ariel G.. Max Planck Institut fĂŒr Extraterrestrische Physik; AlemaniaFil: Salazar Albornoz, Salvador. Max Planck Institut fĂŒr Extraterrestrische Physik; Alemania. Ludwig Maximilians Universitat; AlemaniaFil: Grieb, Jan Niklas. Max Planck Institut fĂŒr Extraterrestrische Physik; Alemania. Ludwig Maximilians Universitat; AlemaniaFil: Vargas Magana, Mariana. Universidad Nacional AutĂłnoma de MĂ©xico; MĂ©xicoFil: Cuesta, Antonio J.. Universidad de Barcelona; EspañaFil: Neyrinck, Mark. University Johns Hopkins; Estados UnidosFil: Beutler, Florian. Lawrence Berkeley National Laboratory; Estados UnidosFil: Comparat, Johan. Universidad AutĂłnoma de Madrid; España. Consejo Superior de Investigaciones CientĂ­ficas; EspañaFil: Percival, Will J.. University of Portsmouth; Reino UnidoFil: Ross, Ashley. Ohio State University; Estados Unidos. University of Portsmouth; Reino Unid

    The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey : tomographic BAO analysis of DR12 combined sample in Fourier space

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    We perform a tomographic baryon acoustic oscillations (BAO) analysis using the monopole, quadrupole and hexadecapole of the redshift-space galaxy power spectrum measured from the pre-reconstructed combined galaxy sample of the completed Sloan Digital Sky Survey Baryon Oscillation Spectroscopic Survey (BOSS) Data Release12 covering the redshift range of 0.20 < z < 0.75. By allowing for overlap between neighbouring redshift slices, we successfully obtained the isotropic and anisotropic BAO distance measurements within nine redshift slices to a precision of 1.5–3.4 per cent for DV/rd, 1.8–4.2 per cent for DA/rd and 3.7–7.5 per cent for H rd, depending on effective redshifts. We provide our BAO measurement of DA/rd and H rd with the full covariance matrix, which can be used for cosmological implications. Our measurements are consistent with those presented in Alam et al., in which the BAO distances are measured at three effective redshifts. We constrain dark energy parameters using our measurements and find an improvement of the Figure-of-Merit of dark energy in general due to the temporal BAO information resolved. This paper is a part of a set that analyses the final galaxy clustering data set from BOSS.PostprintPeer reviewe

    The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey : cosmological implications of the Fourier space wedges of the final sample

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    We extract cosmological information from the anisotropic power-spectrum measurements from the recently completed Baryon Oscillation Spectroscopic Survey (BOSS), extending the concept of clustering wedges to Fourier space. Making use of new fast-Fourier-transform-based estimators, we measure the power-spectrum clustering wedges of the BOSS sample by filtering out the information of Legendre multipoles ℓ > 4. Our modelling of these measurements is based on novel approaches to describe non-linear evolution, bias and redshift-space distortions, which we test using synthetic catalogues based on large-volume N-body simulations. We are able to include smaller scales than in previous analyses, resulting in tighter cosmological constraints. Using three overlapping redshift bins, we measure the angular-diameter distance, the Hubble parameter and the cosmic growth rate, and explore the cosmological implications of our full-shape clustering measurements in combination with cosmic microwave background and Type Ia supernova data. Assuming a Λ cold dark matter (ΛCDM) cosmology, we constrain the matter density to ΩM=0.311+0.009/−0.010 and the Hubble parameter to H0=67.6+0.7/−0.6kms−1 Mpc−1, at a confidence level of 68 per cent. We also allow for non-standard dark energy models and modifications of the growth rate, finding good agreement with the ΛCDM paradigm. For example, we constrain the equation-of-state parameter to w=−1.019+0.048/−0.039. This paper is part of a set that analyses the final galaxy-clustering data set from BOSS. The measurements and likelihoods presented here are combined with others in Alam et al. to produce the final cosmological constraints from BOSS.PreprintPublisher PDFPeer reviewe

    The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: Anisotropic galaxy clustering in Fourier-space

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    We investigate the anisotropic clustering of the Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 12 (DR12) sample, which consists of 1 198 0061\,198\,006 galaxies in the redshift range 0.2<z<0.750.2 < z < 0.75 and a sky coverage of 10 252 10\,252\,deg2^2. We analyse this dataset in Fourier space, using the power spectrum multipoles to measure Redshift-Space Distortions (RSD) simultaneously with the Alcock-Paczynski (AP) effect and the Baryon Acoustic Oscillation (BAO) scale. We include the power spectrum monopole, quadrupole and hexadecapole in our analysis and compare our measurements with a perturbation theory based model, while properly accounting for the survey window function. To evaluate the reliability of our analysis pipeline we participate in a mock challenge, which resulted in systematic uncertainties significantly smaller than the statistical uncertainties. While the high-redshift constraint on fσ8f\sigma_8 at zeff=0.61z_{\rm eff}=0.61 indicates a small (∌1.4σ\sim 1.4\sigma) deviation from the prediction of the Planck Λ\LambdaCDM model, the low-redshift constraint is in good agreement with Planck Λ\LambdaCDM. This paper is part of a set that analyses the final galaxy clustering dataset from BOSS. The measurements and likelihoods presented here are combined with others in~\citet{Alam2016} to produce the final cosmological constraints from BOSS

    The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey:On the measurement of growth rate using galaxy correlation functions

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    We present a measurement of the linear growth rate of structure, \textit{f} from the Sloan Digital Sky Survey III (SDSS III) Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 12 (DR12) using Convolution Lagrangian Perturbation Theory (CLPT) with Gaussian Streaming Redshift-Space Distortions (GSRSD) to model the two point statistics of BOSS galaxies in DR12. The BOSS-DR12 dataset includes 1,198,006 massive galaxies spread over the redshift range 0.2<z<0.750.2 < z < 0.75. These galaxy samples are categorized in three redshift bins. Using CLPT-GSRSD in our analysis of the combined sample of the three redshift bins, we report measurements of fσ8f \sigma_8 for the three redshift bins. We find fσ8=0.430±0.054f \sigma_8 = 0.430 \pm 0.054 at zeff=0.38z_{\rm eff} = 0.38, fσ8=0.452±0.057f \sigma_8 = 0.452 \pm 0.057 at zeff=0.51z_{\rm eff} = 0.51 and fσ8=0.457±0.052f \sigma_8 = 0.457 \pm 0.052 at zeff=0.61z_{\rm eff} = 0.61. Our results are consistent with the predictions of Planck Λ\LambdaCDM-GR. Our constraints on the growth rates of structure in the Universe at different redshifts serve as a useful probe, which can help distinguish between a model of the Universe based on dark energy and models based on modified theories of gravity. This paper is part of a set that analyses the final galaxy clustering dataset from BOSS. The measurements and likelihoods presented here are combined with others in Alam et al. 2016 to produce the final cosmological constraints from BOSS.Comment: This is one of the companion papers of the SDSS DR12 final cosmological result. Submitted to MNRAS. 15 pages, 7 figures, 2 tables. The present draft is a reviewed version submitted to MNRAS after getting reviewer's comment

    The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey : theoretical systematics and Baryon Acoustic Oscillations in the galaxy correlation function

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    We investigate the potential sources of theoretical systematics in the anisotropic Baryon Acoustic Oscillation (BAO) distance scale measurements from the clustering of galaxies in configuration space using the final Data Release (DR12) of the Baryon Oscillation Spectroscopic Survey (BOSS). We perform a detailed study of the impact on BAO measurements from choices in the methodology such as fiducial cosmology, clustering estimators, random catalogues, fitting templates, and covariance matrices. The theoretical systematic uncertainties in BAO parameters are found to be 0.002 in the isotropic dilation α and 0.003 in the quadrupolar dilation Δ. The leading source of systematic uncertainty is related to the reconstruction techniques. Theoretical uncertainties are sub-dominant compared with the statistical uncertainties for BOSS survey, accounting 0.2σstat for α and 0.25σstat for Δ (σα, stat ∌ 0.010 and σΔ, stat ∌ 0.012, respectively). We also present BAO-only distance scale constraints from the anisotropic analysis of the correlation function. Our constraints on the angular diameter distance DA(z) and the Hubble parameter H(z), including both statistical and theoretical systematic uncertainties, are 1.5 per cent and 2.8 per cent at zeff = 0.38, 1.4 per cent and 2.4 per cent at zeff = 0.51, and 1.7 per cent and 2.6 per cent at zeff = 0.61. This paper is part of a set that analyses the final galaxy clustering data set from BOSS. The measurements and likelihoods presented here are cross-checked with other BAO analysis in Alam et al. The systematic error budget concerning the methodology on post-reconstruction BAO analysis presented here is used in Alam et al. to produce the final cosmological constraints from BOSS.PostprintPeer reviewe
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