Combined full shape analysis of BOSS galaxies and eBOSS quasars using an iterative emulator

Standard full-shape clustering analyses in Fourier space rely on a fixed power spectrum template, defined at the fiducial cosmology used to convert redshifts into distances, and compress the cosmological information into the Alcock-Paczynski parameters and the linear growth rate of structure. In this paper, we propose an analysis method that operates directly in the cosmology parameter space and varies the power spectrum template accordingly at each tested point. Predictions for the power spectrum multipoles from the TNS model are computed at different cosmologies in the framework of $\Lambda \rm{CDM}$. Applied to the final eBOSS QSO and LRG samples together with the low-z DR12 BOSS galaxy sample, our analysis results in a set of constraints on the cosmological parameters $\Omega_{\rm cdm}$, $H_0$, $\sigma_8$, $\Omega_{\rm b}$ and $n_s$. To reduce the number of computed models, we construct an iterative process to sample the likelihood surface, where each iteration consists of a Gaussian process regression. This method is validated with mocks from N-body simulations. From the combined analysis of the (e)BOSS data, we obtain the following constraints: $\sigma_8=0.877\pm 0.049$ and $\Omega_{\rm m}=0.304^{+0.016}_{-0.010}$ without any external prior. The eBOSS quasar sample alone shows a $3.1\sigma$ discrepancy compared to the Planck prediction.Comment: 13 pages, 7 figure

The Completed SDSS-IV Extended Baryon Oscillation Spectroscopic Survey: Growth rate of structure measurement from cosmic voids

We present a void clustering analysis in configuration-space using the completed Sloan Digital Sky Survey IV (SDSS-IV) extended Baryon Oscillation Spectroscopic Survey (eBOSS) DR16 samples. These samples consist of Luminous Red Galaxies (LRG) combined with the high redshift tail of the SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS) DR12 CMASS galaxies (called as LRG+CMASS sample), Emission Line Galaxies (ELG) and quasars (QSO). We build void catalogues from the three eBOSS DR16 samples using a ZOBOV-based algorithm, providing 2,814 voids, 1,801 voids and 4,347 voids in the LRG+CMASS, ELG and QSO samples, respectively, spanning the redshift range $0.6<z<2.2$. We measure the redshift space distortions (RSD) around voids using the anisotropic void-galaxy cross-correlation function and we extract the distortion parameter $\beta$. We test the methodology on realistic simulations before applying it to the data, and we investigate all our systematic errors on these mocks. We find $\beta^{\rm LRG}(z=0.74)=0.415\pm0.087$, $\beta^{\rm ELG}(z=0.85)=0.665\pm0.125$ and $\beta^{\rm QSO}(z=1.48)=0.313\pm0.134$, for the LRG+CMASS, ELG and QSO sample, respectively. The quoted errors include systematic and statistical contributions. In order to convert our measurements in terms of the growth rate $f\sigma_8$, we use consensus values of linear bias from the eBOSS DR16 companion papers~\citep{eBOSScosmo}, resulting in the following constraints: $f\sigma_8(z=0.74)=0.50\pm0.11$, $f\sigma_8(z=0.85)=0.52\pm0.10$ and $f\sigma_8(z=1.48)=0.30\pm0.13$. Our measurements are consistent with other measurements from eBOSS DR16 using conventional clustering techniques.Comment: 17 pages, 8 figure

The Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey : pairwise-inverse probability and angular correction for fibre collisions in clustering measurements

HJS is supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics under Award Number DE-SC0014329. Funding for the Sloan Digital Sky Survey IV has been provided by the Alfred P. Sloan Foundation, the U.S. Department of Energy Office of Science, and the Participating Institutions. SDSS-IV acknowledges support and resources from the Center for High-Performance Computing at the University of Utah. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 693024).The completed extended Baryon Oscillation Spectroscopic Survey (eBOSS) catalogues contain redshifts of 344 080 quasars at 0.8 < z < 2.2, 174 816 luminous red galaxies between 0.6 < z < 1.0, and 173 736 emission-line galaxies over 0.6 < z < 1.1 in order to constrain the expansion history of the Universe and the growth rate of structure through clustering measurements. Mechanical limitations of the fibre-fed spectrograph on the Sloan telescope prevent two fibres being placed closer than 62 arcsec in a single pass of the instrument. These ‘fibre collisions’ strongly correlate with the intrinsic clustering of targets and can bias measurements of the two-point correlation function resulting in a systematic error on the inferred values of the cosmological parameters. We combine the new techniques of pairwise-inverse probability and the angular upweighting (PIP+ANG) to correct the clustering measurements for the effect of fibre collisions. Using mock catalogues, we show that our corrections provide unbiased measurements, within data precision, of both the projected wp(rp) and the redshift-space multipole ξ(ℓ = 0, 2, 4)(s) correlation functions down to 0.1h−1Mpc⁠, regardless of the tracer type. We apply the corrections to the eBOSS DR16 catalogues. We find that, on scales s≳20h−1Mpcs≳20h−1Mpc for ξℓ, as used to make baryon acoustic oscillation and large-scale redshift-space distortion measurements, approximate methods such as nearest-neighbour upweighting are sufficiently accurate given the statistical errors of the data. Using the PIP method, for the first time for a spectroscopic program of the Sloan Digital Sky Survey, we are able to successfully access the one-halo term in the clustering measurements down to ∼0.1h−1Mpc scales. Our results will therefore allow studies that use the small-scale clustering to strengthen the constraints on both cosmological parameters and the halo occupation distribution models.Publisher PDFPeer reviewe

The Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Large-scale structure catalogues for cosmological analysis

We present large-scale structure catalogues from the completed extended Baryon Oscillation Spectroscopic Survey (eBOSS). Derived from Sloan Digital Sky Survey (SDSS) IV Data Release 16 (DR16), these catalogues provide the data samples, corrected for observational systematics, and random positions sampling the survey selection function. Combined, they allow large-scale clustering measurements suitable for testing cosmological models. We describe the methods used to create these catalogues for the eBOSS DR16 Luminous Red Galaxy (LRG) and Quasar samples. The quasar catalogue contains 343 708 redshifts with 0.8 1000 km s−1). For quasars, these rates are 95 and 2 per cent (with Δz > 3000 km s−1). We apply corrections for trends between the number densities of our samples and the properties of the imaging and spectroscopic data. For example, the quasar catalogue obtains a χ2/DoF = 776/10 for a null test against imaging depth before corrections and a χ2/DoF= 6/8 after. The catalogues, combined with careful consideration of the details of their construction found here-in, allow companion papers to present cosmological results with negligible impact from observational systematic uncertainties

The Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: measurement of the BAO and growth rate of structure of the luminous red galaxy sample from the anisotropic power spectrum between redshifts 0.6 and 1.0

We analyse the clustering of the Sloan Digital Sky Survey IV extended Baryon Oscillation Spectroscopic Survey Data Release 16 luminous red galaxy sample (DR16 eBOSS LRG) in combination with the high redshift tail of the Sloan Digital Sky Survey III Baryon Oscillation Spectroscopic Survey Data Release 12 (DR12 BOSS CMASS). We measure the redshift space distortions (RSD) and also extract the longitudinal and transverse baryonic acoustic oscillation (BAO) scale from the anisotropic power spectrum signal inferred from 377 458 galaxies between redshifts 0.6 and 1.0, with the effective redshift of zeff = 0.698 and effective comoving volume of 2.72Gpc3⁠. After applying reconstruction, we measure the BAO scale and infer DH(zeff)/rdrag = 19.30 ± 0.56 and DM(zeff)/rdrag = 17.86 ± 0.37. When we perform an RSD analysis on the pre-reconstructed catalogue on the monopole, quadrupole, and hexadecapole we find, DH(zeff)/rdrag = 20.18 ± 0.78, DM(zeff)/rdrag = 17.49 ± 0.52 and fσ8(zeff) = 0.454 ± 0.046. We combine both sets of results along with the measurements in configuration space and report the following consensus values: DH(zeff)/rdrag = 19.77 ± 0.47, DM(zeff)/rdrag = 17.65 ± 0.30 and fσ8(zeff) = 0.473 ± 0.044, which are in full agreement with the standard ΛCDM and GR predictions. These results represent the most precise measurements within the redshift range 0.6 ≤ z ≤ 1.0 and are the culmination of more than 8 yr of SDSS observations.HG-M acknowledges the support from la Caixa Foundation (ID 100010434) which code LCF/BQ/PI18/11630024. RP, SdlT, and SE acknowledge support from the ANR eBOSS project (ANR-16-CE31-0021) of the French National Research Agency. SdlT and SE acknowledge the support of the OCEVU Labex (ANR-11-LABX-0060) and the A*MIDEX project (ANR-11-IDEX-0001-02) funded by the ‘Investissements d’Avenir’ French government program managed by the ANR. MV-M and SF are partially supported by Programa de Apoyo a Proyectos de Investigación e Inovación Teconológica (PAPITT) no. IA101518, no. IA101619 and Proyecto LANCAD-UNAM-DGTIC-136. GR acknowledges support from the National Research Foundation of Korea (NRF) through Grants No. 2017R1E1A1A01077508 and No. 2020R1A2C1005655 funded by the Korean Ministry of Education, Science and Technology (MoEST), and from the faculty research fund of Sejong University. SA is supported by the European Research Council through the COSFORM Research Grant (#670193). E-MM is supported by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 693024).Peer reviewe

A História da Alimentação: balizas historiográficas

Os M. pretenderam traçar um quadro da História da Alimentação, não como um novo ramo epistemológico da disciplina, mas como um campo em desenvolvimento de práticas e atividades especializadas, incluindo pesquisa, formação, publicações, associações, encontros acadêmicos, etc. Um breve relato das condições em que tal campo se assentou faz-se preceder de um panorama dos estudos de alimentação e temas correia tos, em geral, segundo cinco abardagens Ia biológica, a econômica, a social, a cultural e a filosófica!, assim como da identificação das contribuições mais relevantes da Antropologia, Arqueologia, Sociologia e Geografia. A fim de comentar a multiforme e volumosa bibliografia histórica, foi ela organizada segundo critérios morfológicos. A seguir, alguns tópicos importantes mereceram tratamento à parte: a fome, o alimento e o domínio religioso, as descobertas européias e a difusão mundial de alimentos, gosto e gastronomia. O artigo se encerra com um rápido balanço crítico da historiografia brasileira sobre o tema

Cosmological constraints with large spectroscopic survey of quasars of eBOSS/SDSS-IV

Durant ma thèse, l'objectif était d'étudier la structuration de l'échantillon de quasars de eBOSS au travers de son spectre de puissance. D'une part, nous nous sommes focalisés sur les oscillations acoustiques de baryons pour contraindre DM/rd et DH/rd. D'autre part, nous avons modélisé la forme complète du spectre de puissance pour ajouter une contrainte sur le taux de croissance des structures fσ ₈. Ces modèles ont été testés sur des mocks construits à partir d'une simulation à N-corps. Nous avons testé l’incertitude en redshift particulière aux quasars dans le cadre de ce extitmock challenge. Nous avons implémenté un terme de Finger-of-God permettant de prendre en compte ces incertitudes non-gaussiennes. Nous avons testé nos modèles sur des mocks dont la cosmologie nous était inconnue. Cela a mis en évidence un décalage des paramètres si notre cosmologie fiducielle est trop éloignée de la cosmologie réelle du relevé. Ce décalage n'est pas significatif pour le relevé de eBOSS mais peut être problématique pour les futurs relevés spectroscopiques. Ensuite, testé les effets systématiques de notre relevé sur des mocks rapides ayant la même géométrie que les données. Nous avons implémenté les effets systématiques observationnels sur ces mocks. Nous avons mis en évidence un décalage du spectre de puissance par l'implémentation des collisions de fibres, nous manquons ~ 40% des paires à petite échelle perpendiculairement à la ligne de visée. Nous l'avons modélisé dans le spectre de puissance en ajoutant une fonction de sélection à ces échelles. Pour les deux modèles, l'erreur systématique totale est inférieure ou égale à 30% de l'erreur statistique pour chacun des paramètres, la plus importante part provenant de la modélisation du spectre. Nous avons combiné notre analyse et l'analyse du même catalogue de quasars en espace de configuration, ce qui amène à des contraintes de DH/rd = 13.26 ± 0.55 et DM/rd = 30.69 ± 0.80 pour l'analyse BAO uniquement; et DH/rd = 13.23 ± 0.47, DM/rd =30.21 ± 0.79 et fσ ₈ =0.462 ± 0.045 pour l'analyse de la forme complète du spectre de puissance. Ces mesures sont en accord avec les analyses du CMB; la mesure du taux de croissance linéaire des structures, fσ ₈ est plus haut de 1.9σ en comparaison de la valeur de Planck. En utilisant toutes les mesures des analyses de la structuration des galaxies de SDSS, nous apportons d'importantes contraintes des paramètres cosmologiques. Ensuite, nous avons cherché à ce que notre analyse de la forme complète du spectre de puissance ne dépende pas de la cosmologie fiducielle. Nous analysons le spectre de puissance observé à l'aide de plusieurs modèles avec différents paramètres cosmologiques, les paramètres informatifs de notre ajustement sont fixés à leur valeur ΛCDM+GR pour ensuite interpoler, à l'aide d'un processus gaussien, la nappe de χ² sur l'espace des paramètres cosmologiques pour ajuster ces derniers. Cela permet de ne pas compresser l'information. Ce faisant, nous ajustons l'ensemble des paramètres cosmologiques sans a priori provenant de sondes externes comme cela est habituellement fait dans les analyses de la structuration de galaxies. En analysant le relevé de quasars, nous augmentons le désaccord avec Planck sur l'amplitude des fluctuations de matière, σ₈, à 3.1σ. Notre analyse conjointe des relevés de quasars et de LRG de eBOSS ainsi que du relevé low-z de BOSS est en accord avec l'analyse de Planck. Nous obtenons des contraintes plus fortes sur Ωm qu'avec les analyses standard de SDSS. Cette méthode pourra être utilisée dans le cadre des futurs grands relevés spectroscopiques tel que DESI ou Euclid pour minimiser l'erreur systématique due au modèle tout en améliorant les contraintes statistiques.During my thesis, the objective was to study the clustering of the sample of eBOSS quasars through its power spectrum. On the one hand, we focused on the acoustic oscillations of baryons to constrain DM/rd et DH/rd. On the other hand, we modelled the full shape of the power spectrum to add a constraint on the growth rate of the structures fσ ₈. These models were tested on mocks built from an N-body simulation. We tested the redshift uncertainty specific to quasars as part of this extitmock challenge. We implemented a Finger-of-God term to take into account these non-Gaussian uncertainties. We tested our models on mocks whose cosmology was unknown to us. This highlighted a shift in the parameters if our fiducial cosmology is too far from the real cosmology of the survey. This shift is not significant for eBOSS survey but can be problematic for future spectroscopic surveys. Then, we tested the systematic effects of our survey on fast mocks with the same geometry as the data. We implemented the systematic observational effects on these mocks. We have demonstrated a shift in the power spectrum by the implementation of fibre collisions, we are missing ~ 40% of small scale pairs perpendicular to the line of sight. We model it in the power spectrum by adding a window function to these scales. For both models, the total systematic error is lower than or equal to 30% of the statistical error for each parameter, the largest part coming from spectrum modelling. We combined our analysis and the analysis of the same catalog of quasars in configuration space, which leads to constraints of DH/rd = 13.26 ± 0.55 and DM/rd = 30.69 ± 0.80 for BAO-only analysis; and DH/rd = 13.23 ± 0.47, DM/rd =30.21 ± 0.79 and fσ ₈ =0.462 ± 0.045 for the analysis of the full shape of the power spectrum. These measurements are in agreement with the analyzes of the CMB; the measurement of the linear growth rate of structures, fσ ₈ is 1.9σ higher compared to Planck's value. Using all the measurements from the galaxy clustering analyzes of SDSS, we bring important constraints of cosmological parameters such as the equation of state of l dark energy or the curvature of the universe. Next, we sought to ensure that our analysis of the full shape of the power spectrum did not depend on fiducial cosmology. We analyze the observed power spectrum using several model with different cosmological parameters, the informative parameters of our fit are set to their value ΛCDM+GR and then interpolate, using a Gaussian process, the χ² map over the space of cosmological parameters to fit the latter. This allows to not compressing the information. In doing so, we adjust the set of cosmological parameters without any prior coming from external probes as is usually done in analyzes of the structuring of galaxies. By analyzing the quasar survey, we increase the disagreement with Planck on the amplitude of the fluctuations of matter, σ₈, to 3.1σ. Our combined analysis of eBOSS quasar and LRG surveys, as well as the BOSS low-z surveys, is in agreement with Planck's analysis. We obtain stronger constraints on Ωm than with the standard analyzes of SDSS. This method could be used within the framework of future large spectroscopic surveys such as DESI or Euclid to minimize the systematic error due to the model while improving the statistical constraints

Contraintes cosmologiques avec le grand relevé spectroscopique de quasars de eBOSS/SDSS-IV

During my thesis, the objective was to study the clustering of the sample of eBOSS quasars through its power spectrum. On the one hand, we focused on the acoustic oscillations of baryons to constrain DM/rd et DH/rd. On the other hand, we modelled the full shape of the power spectrum to add a constraint on the growth rate of the structures fσ ₈. These models were tested on mocks built from an N-body simulation. We tested the redshift uncertainty specific to quasars as part of this extitmock challenge. We implemented a Finger-of-God term to take into account these non-Gaussian uncertainties. We tested our models on mocks whose cosmology was unknown to us. This highlighted a shift in the parameters if our fiducial cosmology is too far from the real cosmology of the survey. This shift is not significant for eBOSS survey but can be problematic for future spectroscopic surveys. Then, we tested the systematic effects of our survey on fast mocks with the same geometry as the data. We implemented the systematic observational effects on these mocks. We have demonstrated a shift in the power spectrum by the implementation of fibre collisions, we are missing ~ 40% of small scale pairs perpendicular to the line of sight. We model it in the power spectrum by adding a window function to these scales. For both models, the total systematic error is lower than or equal to 30% of the statistical error for each parameter, the largest part coming from spectrum modelling. We combined our analysis and the analysis of the same catalog of quasars in configuration space, which leads to constraints of DH/rd = 13.26 ± 0.55 and DM/rd = 30.69 ± 0.80 for BAO-only analysis; and DH/rd = 13.23 ± 0.47, DM/rd =30.21 ± 0.79 and fσ ₈ =0.462 ± 0.045 for the analysis of the full shape of the power spectrum. These measurements are in agreement with the analyzes of the CMB; the measurement of the linear growth rate of structures, fσ ₈ is 1.9σ higher compared to Planck's value. Using all the measurements from the galaxy clustering analyzes of SDSS, we bring important constraints of cosmological parameters such as the equation of state of l dark energy or the curvature of the universe. Next, we sought to ensure that our analysis of the full shape of the power spectrum did not depend on fiducial cosmology. We analyze the observed power spectrum using several model with different cosmological parameters, the informative parameters of our fit are set to their value ΛCDM+GR and then interpolate, using a Gaussian process, the χ² map over the space of cosmological parameters to fit the latter. This allows to not compressing the information. In doing so, we adjust the set of cosmological parameters without any prior coming from external probes as is usually done in analyzes of the structuring of galaxies. By analyzing the quasar survey, we increase the disagreement with Planck on the amplitude of the fluctuations of matter, σ₈, to 3.1σ. Our combined analysis of eBOSS quasar and LRG surveys, as well as the BOSS low-z surveys, is in agreement with Planck's analysis. We obtain stronger constraints on Ωm than with the standard analyzes of SDSS. This method could be used within the framework of future large spectroscopic surveys such as DESI or Euclid to minimize the systematic error due to the model while improving the statistical constraints.Durant ma thèse, l'objectif était d'étudier la structuration de l'échantillon de quasars de eBOSS au travers de son spectre de puissance. D'une part, nous nous sommes focalisés sur les oscillations acoustiques de baryons pour contraindre DM/rd et DH/rd. D'autre part, nous avons modélisé la forme complète du spectre de puissance pour ajouter une contrainte sur le taux de croissance des structures fσ ₈. Ces modèles ont été testés sur des mocks construits à partir d'une simulation à N-corps. Nous avons testé l’incertitude en redshift particulière aux quasars dans le cadre de ce extitmock challenge. Nous avons implémenté un terme de Finger-of-God permettant de prendre en compte ces incertitudes non-gaussiennes. Nous avons testé nos modèles sur des mocks dont la cosmologie nous était inconnue. Cela a mis en évidence un décalage des paramètres si notre cosmologie fiducielle est trop éloignée de la cosmologie réelle du relevé. Ce décalage n'est pas significatif pour le relevé de eBOSS mais peut être problématique pour les futurs relevés spectroscopiques. Ensuite, testé les effets systématiques de notre relevé sur des mocks rapides ayant la même géométrie que les données. Nous avons implémenté les effets systématiques observationnels sur ces mocks. Nous avons mis en évidence un décalage du spectre de puissance par l'implémentation des collisions de fibres, nous manquons ~ 40% des paires à petite échelle perpendiculairement à la ligne de visée. Nous l'avons modélisé dans le spectre de puissance en ajoutant une fonction de sélection à ces échelles. Pour les deux modèles, l'erreur systématique totale est inférieure ou égale à 30% de l'erreur statistique pour chacun des paramètres, la plus importante part provenant de la modélisation du spectre. Nous avons combiné notre analyse et l'analyse du même catalogue de quasars en espace de configuration, ce qui amène à des contraintes de DH/rd = 13.26 ± 0.55 et DM/rd = 30.69 ± 0.80 pour l'analyse BAO uniquement; et DH/rd = 13.23 ± 0.47, DM/rd =30.21 ± 0.79 et fσ ₈ =0.462 ± 0.045 pour l'analyse de la forme complète du spectre de puissance. Ces mesures sont en accord avec les analyses du CMB; la mesure du taux de croissance linéaire des structures, fσ ₈ est plus haut de 1.9σ en comparaison de la valeur de Planck. En utilisant toutes les mesures des analyses de la structuration des galaxies de SDSS, nous apportons d'importantes contraintes des paramètres cosmologiques. Ensuite, nous avons cherché à ce que notre analyse de la forme complète du spectre de puissance ne dépende pas de la cosmologie fiducielle. Nous analysons le spectre de puissance observé à l'aide de plusieurs modèles avec différents paramètres cosmologiques, les paramètres informatifs de notre ajustement sont fixés à leur valeur ΛCDM+GR pour ensuite interpoler, à l'aide d'un processus gaussien, la nappe de χ² sur l'espace des paramètres cosmologiques pour ajuster ces derniers. Cela permet de ne pas compresser l'information. Ce faisant, nous ajustons l'ensemble des paramètres cosmologiques sans a priori provenant de sondes externes comme cela est habituellement fait dans les analyses de la structuration de galaxies. En analysant le relevé de quasars, nous augmentons le désaccord avec Planck sur l'amplitude des fluctuations de matière, σ₈, à 3.1σ. Notre analyse conjointe des relevés de quasars et de LRG de eBOSS ainsi que du relevé low-z de BOSS est en accord avec l'analyse de Planck. Nous obtenons des contraintes plus fortes sur Ωm qu'avec les analyses standard de SDSS. Cette méthode pourra être utilisée dans le cadre des futurs grands relevés spectroscopiques tel que DESI ou Euclid pour minimiser l'erreur systématique due au modèle tout en améliorant les contraintes statistiques