SPT-3G: Cosmology from CMB Lensing and Delensed EE Power Spectra with 2019 and 2020 Polarization Data

Data taken with SPT-3G, the third-generation CMB camera on the South Pole Telescope (SPT), has been used to produce the deepest high-angular-resolution CMB polarization maps at 90, 150, and 220 GHz to date. At these depths, it is possible to extract information from CMB lensing beyond the standard quadratic estimator (QE) method for lensing reconstruction. The Marginal Unbiased Score Expansion (MUSE) method enables an optimal map-level Bayesian inference of lensing potential bandpowers and unlensed CMB EE bandpowers, effectively using all N-point statistics of the CMB polarization maps. The resulting EE spectrum at l>2000 and lensing spectrum at L>350 are the most precise to date. I will present these power spectra and the resulting cosmological constraints, which are comparable to those from Planck, particularly for the Hubble constant (H₀) and the amplitude of structure growth (S₈), enabling a powerful test of the LCDM model. We also use these optimally estimated spectra to test the anomaly of excess lensing power from the LCDM prediction, to detect the impact of non-linear structure evolution on CMB lensing, and to explore extensions of the LCDM model.