An analysis of parameter compression and Full-Modeling techniques with Velocileptors for DESI 2024 and beyond
M Maus, S. Chen, Martin White, José Aguilar, S. P. Ahlen, Alejandro Avilés, S. Brieden, D. Brooks, T. Claybaugh, S. Cole, Axel de la Macorra, Arjun Dey, P. Doel, S Ferraro, N. Findlay, J. E. Forero-Romero, E. Gaztañaga, Héctor Gil-Marín, Satya Gontcho A Gontcho, ChangHoon Hahn, K. Honscheid, Cullan Howlett, Mustapha Ishak, S. Juneau, Anthony Kremin, Ying‐Cheng Lai, Martin Landriau, M. E. Levi, Marc Manera, R. Miquel, Eva-Maria Mueller, Adam D. Myers, S. Nadathur, Jundan Nie, H. E. Noriega, N. Palanque‐Delabrouille, Will J. Percival, Claire Poppett, S. Ramírez-Solano, Mehdi Rezaie, A. Rocher, Graziano Rossi, E. Sánchez, David J. Schlegel, M. Schubnell, Hee‐Jong Seo, David Sprayberry, G. Tarlé, M. Vargas-Magaña, Benjamin Alan Weaver, Sihan Yuan, Pauline Zarrouk, H Zhang, R. Zhou, H. Zou
Abstract
Abstract In anticipation of forthcoming data releases of current and future spectroscopic surveys, we present the validation tests and analysis of systematic effects within velocileptors modeling pipeline when fitting mock data from the AbacusSummit N-body simulations. We compare the constraints obtained from parameter compression methods to the direct fitting (Full-Modeling) approaches of modeling the galaxy power spectra, and show that the ShapeFit extension to the traditional template method is consistent with the Full-Modeling method within the standard ΛCDM parameter space. We show the dependence on scale cuts when fitting the different redshift bins using the ShapeFit and Full-Modeling methods. We test the ability to jointly fit data from multiple redshift bins as well as joint analysis of the pre-reconstruction power spectrum with the post-reconstruction BAO correlation function signal. We further demonstrate the behavior of the model when opening up the parameter space beyond ΛCDM and also when combining likelihoods with external datasets, namely the Planck CMB priors. Finally, we describe different parametrization options for the galaxy bias, counterterm, and stochastic parameters, and employ the halo model in order to physically motivate suitable priors that are necessary to ensure the stability of the perturbation theory.