James Morawetz, Hanyu Zhang, Marco Bonici, Will J. Percival, Andrea Crespi, J. Aguilar, S. P. Ahlen, D. Bianchi, David J. Brooks, F. J. Castander, T. Claybaugh, Shaun Cole, Andrei Cuceu, Axel de la Macorra, Arnaud de Mattia, Biprateep Dey, P. Doel, Simone Ferraro, Andreu Font-Ribera, J. E. Forero-Romero, E. Gaztañaga, Satya Gontcho A Gontcho, G. Gutiérrez, Chang Hoon Hahn, Klaus Honscheid, Dragan Huterer, Mustapha Ishak, Dick Joyce, R. Kehoe, D. Kirkby, T. Kisner, Ofer Lahav, A. Lambert, Martin Landriau, L. Le Guillou, Marc Manera, R. Miquel, E. Mueller, S. Nadathur, J.A. Newman, Gustavo Niz, N. Palanque‐Delabrouille, Francisco Prada, Ignasi Pérez-Ràfols, Graziano Rossi, Lado Samushia, E. Sánchez, David J. Schlegel, M Schubnell, J. Silber, D. Sprayberry, G. Tarlé, Benjamin Alan Weaver, Pauline Zarrouk, R. Zhou, Hu Zou
Abstract We present a frequentist analysis of clustering measurements from Data Release 1 of the Dark Energy Spectroscopic Instrument (DESI) using the standard profile likelihood method. While Bayesian inferences for effective field theory models of galaxy clustering can be highly sensitive to prior choices for extended cosmological models, frequentist inferences are not susceptible to such effects. We compare frequentist and Bayesian constraints for the parameter set { σ 8 , H 0 , Ω m , w 0 , w a } using the full-shape power spectrum multipoles, post-reconstruction baryon acoustic oscillation (BAO) measurements, and external datasets from the CMB and type Ia supernovae measurements. The frequentist confidence intervals are significantly shifted relative to the Bayesian credible intervals for the w 0 w a CDM model, unless supernovae data are included. When DESI full-shape and BAO data are fit jointly, we obtain the following 1 σ frequentist confidence intervals for ΛCDM ( w 0 w a CDM): σ 8 = 0.863 +0.048 -0.040 , H 0 = 68.96 +0.81 -0.80 km s -1 Mpc -1 , Ω m = 0.3034 ± 0.0110 ( σ 8 = 0.782 +0.060 -0.036 , H 0 = 63.7 +4.2 -2.0 km s -1 Mpc -1 , Ω m = 0.378 +0.024 -0.047 , w 0 = -0.16 +0.10 -0.50 , w a = -3.0 +1.7 ), corresponding to 0.8 σ , 0.3 σ , 0.7 σ (2.1 σ , 4.1 σ , 6.5 σ , 6.3 σ , 6.6 σ ) shifts between the maximum likelihood estimate and the Bayesian posterior mean for ΛCDM ( w 0 w a CDM) respectively.