Foreground-Immune Curved-Sky Lensing Reconstruction with SPT-3G 2019+2020 Data

Weak gravitational lensing of the cosmic microwave background (CMB) is a powerful probe of fundamental physics, and offers insight into the structure and evolution of the universe. SPT-3G is an ongoing high angular resolution and low noise CMB experiment providing ideal temperature and polarization maps for the purpose of reconstructing the lensing potential. For the upcoming SPT-3G lensing analysis using data collected during the 2019 and 2020 observing seasons, we use the global minimum variance (GMV) estimator in the curved sky formalism, which is shown to have up to a 10% improvement in noise compared to the standard quadratic estimator. With this estimator, we expect the statistical uncertainty on the lensing amplitude to be about 2% for this analysis. In this talk, we present an extension to the GMV estimator with various foreground mitigation techniques, which makes our measurements more robust against contamination from astrophysical sources. We also discuss the cosmological parameter results from the 2019-2020 SPT-3G lensing measurements.