Full-Shape analysis of the power spectrum and bispectrum of DESI DR1 LRG and QSO samples
Sergi Novell-Masot, Héctor Gil-Marín, Licia Verde, J. Aguilar, S. P. Ahlen, S. Bailey, S. BenZvi, D. Bianchi, D. Brooks, E. Buckley‐Geer, A. Carnero Rosell, E. Chaussidon, T. Claybaugh, Shaun Cole, Andrei Cuceu, Kyle Dawson, Axel de la Macorra, R. Demina, Arjun Dey, Biprateep Dey, Peter Doel, Simone Ferraro, Andreu Font-Ribera, J. E. Forero-Romero, E. Gaztañaga, Satya Gontcho A Gontcho, Alma X. González‐Morales, G. Gutiérrez, H. K. Herrera-Alcantar, K. Honscheid, Cullan Howlett, S. Juneau, R. Kehoe, D. Kirkby, Theodore Kisner, Anthony Kremin, C. Lamman, Martin Landriau, L. Le Guillou, M. E. Levi, C. Magneville, Marc Manera, Aaron Meisner, R. Miquel, John Moustakas, A. Muñoz-Gutiérrez, Adam D. Myers, S. Nadathur, Gustavo Niz, H. E. Noriega, Will J. Percival, C. Poppett, Francisco Prada, Ignasi Pérez-Ràfols, Ashley J. Ross, Graziano Rossi, Lado Samushia, E. Sánchez, David J. Schlegel, M. Schubnell, Hee‐Jong Seo, J. Silber, D. Sprayberry, G. Tarlé, M. Vargas-Magaña, B. A. Weaver, Pauline Zarrouk, Rongpu Zhou, Hu Zou
Abstract
Abstract 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, σ s8 ( z ), which cannot be measured separately in analyses that only involve the power spectrum. In comparison with the (fiducial) Planck ΛCDM cosmology we obtain f / f fid = {0.888 -0.089 +0.186 ,0.977 -0.220 +0.182 ,1.030 -0.085 +0.368 }, σ s8 / σ fid s8 = {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 σ s8 , including the systematic error budget. Additionally, we obtain constraints for the ShapeFit compressed parameters describing the isotropic scaling parameter, α iso ( z ), the Alcock-Paczyński parameter, α AP ( z ), the combined growth of structure parameter fσ s8 ( z ), and the combined shape parameter m ( z )+ n ( z ). Their cumulative constraints from our joint power spectrum-bispectrum analysis are respectively σ α iso = 0.9% (9% improvement with respect to our power spectrum-only analysis); σ α AP = 2.3% (no improvement with respect to power spectrum-only analysis, which is expected given that the bispectrum monopole has no significant anisotropic signal); σ fσ s8 = 5.1% (9% improvement); σ m+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 ΛCDM cosmology.