CMB Lensing Measurements with Two Years of Data from the SPT-3G Survey

The South Pole Telescope (SPT) is a 10 m offset Gregorian telescope designed to observe the Cosmic Microwave Background (CMB) and astrophysical foregrounds at millimeter wavelengths. Radiation from the CMB is gravitationally lensed by large scale structure as it travels through the cosmos, complicating the analysis of the primordial CMB but also embedding information about the evolution and structure of the universe at more recent times. Measurements of the lensing potential can be used to constrain cosmological parameters (e.g. Ω_M, σ_8, and the sum of neutrino masses) and to remove lensing contamination from CMB B-mode polarization maps in the search for primordial gravitational waves. The SPT-3G experiment surveys 1500 deg² of the southern sky with ~1 arcminute angular resolution, allowing for high signal-to-noise measurements of the lensing potential out to sub-degree scales that can probe the nonlinear regime of the lensing power spectrum. In this talk I will present preliminary results from the latest SPT lensing analysis using data from the 2019 and 2020 observing seasons. The resulting lensing maps will be some of most sensitive made to date, and will be combined with BICEP/Keck data to tighten the constraints on the amplitude of primordial gravitational waves.