2026-04-17T00:23:27Zhttps://recercat.cat/oai/request

oai:recercat.cat:2117/4463222026-02-05T02:34:10Zcom_2072_1033col_2072_452950

00925njm 22002777a 4500 dc Novell Masot, Sergi author Gil Marín, Héctor author Verde, Licia author Aguilar, Jessica Nicole author Ahlen, Steven author Bailey, Steven author Benzvi, Segev author Bianchi, Davide author Brooks, David author Pérez Ràfols, Ignasi author 2025-06-01 We present the first joint analysis of the power spectrum and bispectrum using the Data Release 1 (DR1) of the Dark Energy Spectroscopic Instrument (DESI), focusing on Luminous Red Galaxies (LRGs) and quasars (QSOs) across a redshift range of 0.4 = z = 2.1. By combining the two- and three-point statistics, we are able to partially break the degeneracy between the logarithmic growth rate, f(z), and the amplitude of dark matter fluctuations, ss8(z), which cannot be measured separately in analyses that only involve the power spectrum. In comparison with the (fiducial) Planck ¿CDM cosmology we obtain f/ffid = {0.888-0.089+0.186,0.977-0.220+0.182,1.030-0.085+0.368}, ss8/sfids8 = {1.224-0.133+0.091,1.071-0.163+0.278,1.00 0-0.223+0.088} respectively for the three LRG redshift bins, corresponding to a cumulative 10.1% constraint on f, and of 8.4% on ss8, including the systematic error budget. Additionally, we obtain constraints for the ShapeFit compressed parameters describing the isotropic scaling parameter, aiso(z), the Alcock-Paczynski parameter, aAP(z), the combined growth of structure parameter fss8(z), and the combined shape parameter m(z)+n(z). Their cumulative constraints from our joint power spectrum-bispectrum analysis are respectively saiso = 0.9% (9% improvement with respect to our power spectrum-only analysis); saAP = 2.3% (no improvement with respect to power spectrum-only analysis, which is expected given that the bispectrum monopole has no significant anisotropic signal); sfss8 = 5.1% (9% improvement); sm+n = 2.3% (11% improvement). These results are fully consistent with the main DESI power spectrum analysis, demonstrating the robustness of the DESI cosmological constraints, and compatible with Planck ¿CDM cosmology. Postprint (published version) Àrees temàtiques de la UPC::Física::Astronomia i astrofísica Cosmological parameters from LSS Power spectrum Redshift surveys Full-Shape analysis of the power spectrum and bispectrum of DESI DR1 LRG and QSO samples