Testing the $\mathbf{\Lambda}$CDM Cosmological Model with Forthcoming Measurements of the Cosmic Microwave Background with SPT-3G

• Main Authors: Prabhu, K, Raghunathan, S, Millea, M, Lynch, G.P, Ade, P.A.R, Anderes, E, Anderson, A.J, Ansarinejad, B, Archipley, M, Balkenhol, L, Benabed, K, Bender, A.N, Benson, B.A, Bianchini, F, Bleem, L.E, Bouchet, F.R, Bryant, L, Camphuis, E, Carlstrom, J.E, Cecil, T.W, Chang, C.L, Chaubal, P, Chichura, P.M, Chou, T.-L, Coerver, A, Crawford, T.M, Cukierman, A, Daley, C, de Haan, T, Dibert, K.R, Dobbs, M.A, Doussot, A, Dutcher, D, Everett, W, Feng, C, Ferguson, K.R, Fichman, K, Foster, A, Galli, S, Gambrel, A.E, Gardner, R.W, Ge, F, Goeckner-Wald, N, Gualtieri, R, Guidi, F, Guns, S, Halverson, N.W, Hivon, E, Holder, G.P, Holzapfel, W.L, Hood, J.C, Hryciuk, A, Huang, N, Kéruzoré, F, Knox, L, Korman, M, Kornoelje, K, Kuo, C.-L, Lee, A.T, Levy, K, Lowitz, A.E, Lu, C, Maniyar, A, Menanteau, F, Montgomery, J, Nakato, Y, Natoli, T, Noble, G.I, Novosad, V, Omori, Y, Padin, S, Pan, Z, Paschos, P, Phadke, K.A, Quan, W, Rahimi, M, Rahlin, A, Reichardt, C.L, Rouble, M, Ruhl, J.E, Schiappucci, E, Smecher, G, Sobrin, J.A, Stark, A.A, Stephen, J, Suzuki, A, Tandoi, C, Thompson, K.L, Thorne, B, Trendafilova, C, Tucker, C, Umilta, C, Vitrier, A, Vieira, J.D, Wan, Y, Wang, G, Whitehorn, N, Wu, W.L.K, Yefremenko, V, Young, M.R, Zebrowski, J.A
• Other Authors: Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), SPT-3G
• Format: Report
• Language: English
• Published: HAL CCSD 2024
• Subjects: [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]; Lambda; South Pole; South pole
• Online Access: https://hal.science/hal-04537707

International audience We forecast constraints on cosmological parameters enabled by three surveys conducted with SPT-3G, the third-generation camera on the South Pole Telescope. The surveys cover separate regions of 1500, 2650, and 6000 ${\rm deg}^{2}$ to different depths, in total observing 25% of the sky. These regions will be measured to white noise levels of roughly 2.5, 9, and 12 $\mu{\rm K-arcmin}$, respectively, in CMB temperature units at 150 GHz by the end of 2024. The survey also includes measurements at 95 and 220 GHz, which have noise levels a factor of ~1.2 and 3.5 times higher than 150 GHz, respectively, with each band having a polarization noise level ~$\sqrt{\text{2}}$ times higher than the temperature noise. We use a novel approach to obtain the covariance matrices for jointly and optimally estimated gravitational lensing potential bandpowers and unlensed CMB temperature and polarization bandpowers. We demonstrate the ability to test the $\Lambda{\rm CDM}$ model via the consistency of cosmological parameters constrained independently from SPT-3G and Planck data, and consider the improvement in constraints on $\Lambda{\rm CDM}$ extension parameters from a joint analysis of SPT-3G and Planck data. The $\Lambda{\rm CDM}$ cosmological parameters are typically constrained with uncertainties up to ~2 times smaller with SPT-3G data, compared to Planck, with the two data sets measuring significantly different angular scales and polarization levels, providing additional tests of the standard cosmological model.