Joint cosmological fits to DESI-DR1 full-shape clustering and weak gravitational lensing in configuration space

Le résumé fourni par la source

We present a joint 3 × 2 -pt cosmological analysis of auto- and cross-correlations between the Dark Energy Spectroscopic Instrument Data Release 1 (DESI-DR1) Bright Galaxy Survey (BGS) and Luminous Red Galaxy (LRG) samples and overlapping shear measurements from the KiDS-1000, DES-Y3 and HSC-Y3 weak lensing surveys. We perform our analysis in configuration space and, in addition to the cosmic shear correlation functions for each weak lensing dataset, we fit the tangential shear of the weak lensing source galaxies around DESI lens galaxies. Finally, we make use of the anisotropic BGS and LRG clustering information by fitting the full shape of the two-point correlation function multipoles measured over the full DESI-DR1 footprint, presenting the first full-shape analysis of DESI measurements in configuration space. We find that the addition of weak lensing information serves to improve, with respect to the clustering-only case, the measurements of the power spectrum amplitude parameters and σ 12 by 15 % and 36 % , respectively. It also improves measurements of the linear bias of the lens galaxies by 15 − 20 % , depending on the tracer. Our results show excellent consistency, regardless of the weak lensing survey considered, and are furthermore consistent with a companion analysis that fits 3 × 2 -pt correlations including DESI projected clustering measurements, as well as the results published by the weak lensing collaborations themselves. Our measured values for weak lensing amplitude are S 8 D E S I × H S C = 0.787 ± 0.020 , S 8 D E S I × D E S = 0.791 ± 0.016 , S 8 D E S I × K i D S = 0.771 ± 0.017 , which are 1.9 σ − 2.9 σ below the S 8 value preferred by Planck. Finally, our clustering-only results are in good agreement with the Fourier space full-shape analysis of all DESI tracers, although we see some indications of the presence of projection effects. This work paves the way for future ‘same-sky’ analyses of cross-correlations between the upcoming DESI data releases and overlapping shear datasets.

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