We test the smooth dark energy paradigm using Dark Energy Survey (DES) year 1 and year 3 weak lensing and galaxy clustering data. Within the ΛCDM and wCDM model we separate the expansion and structure growth history by splitting ωm (and w) into two metaparameters that allow for different evolution of growth and geometry in the Universe. We consider three different combinations of priors on geometry from CMB, SNIa, BAO, BBN that differ in constraining power but have been designed such that the growth information comes solely from the DES weak lensing and galaxy clustering. For the DES-Y1 data we find no detectable tension between growth and geometry metaparameters in both the ΛCDM and wCDM parameter space. This statement also holds for DES-Y3 cosmic shear and 3×2 pt analyses. For the combination of DES-Y3 galaxy-galaxy lensing and galaxy clustering (2×2 pt) we measure a tension between our growth and geometry metaparameters of 2.6σ in the ΛCDM and 4.48σ in the wCDM model space, respectively. We attribute this tension to residual systematics in the DES-Y3 redmagic galaxy sample rather than to new physics. We plan to investigate our findings further using alternative lens samples in DES-Y3 and future weak lensing and galaxy clustering datasets.
ASJC Scopus subject areas
- Nuclear and High Energy Physics