Paper
The Pantheon+ Analysis: Cosmological Constraints
Authors
D. Brout, D. Scolnic, B. Popovic, A. Riess, A. Carr, J. Zuntz, R. Kessler, T. Davis, S. Hinton, David O. Jones, D. W., Arcy Kenworthy, E. Peterson, K. Said, G. Taylor, Noor Ali, P. Armstrong, Pranav Charvu, Arianna M. Dwomoh, C. Meldorf, A. Palmese, H. Qu, B. Rose, B. Sanchez, C. Stubbs, Marian Vincenzi, C. Wood, P. Brown, Rebecca Chen, K. Chambers, D. Coulter, M. Dai, G. Dimitriadis, A. Filippenko, R. Foley, S. Jha, L. Kelsey, R. Kirshner, A. Möller, J. Muir, S. Nadathur, Yen-Chen Pan, A. Rest, C. Rojas-Bravo, M. Sako, M. Siebert, Matthew C. Smith, B. Stahl, P. Wiseman
Abstract
We present constraints on cosmological parameters from the Pantheon+ analysis of 1701 light curves of 1550 distinct Type Ia supernovae (SNe Ia) ranging in redshift from to 2.26. This work features an increased sample size, increased redshift span, and improved treatment of systematic uncertainties in comparison to the original Pantheon analysis and results in a factor of two improvement in cosmological constraining power. For a FlatCDM model, we find from SNe Ia alone. For a FlatCDM model, we measure from SNe Ia alone, H km s Mpc when including the Cepheid host distances and covariance (SH0ES), and when combining the SN likelihood with constraints from the cosmic microwave background (CMB) and baryon acoustic oscillations (BAO); both values are consistent with a cosmological constant. We also present the most precise measurements to date on the evolution of dark energy in a FlatCDM universe, and measure from Pantheon+ alone, H km s Mpc when including SH0ES, and when combining Pantheon+ with CMB and BAO data. Finally, we find that systematic uncertainties in the use of SNe Ia along the distance ladder comprise less than one third of the total uncertainty in the measurement of H and cannot explain the present "Hubble tension" between local measurements and early-Universe predictions from the cosmological model.