Cross-correlations of galaxy positions and galaxy shears with maps of gravitational lensing of the cosmic microwave background (CMB) are sensitive to the distribution of large-scale structure in the Universe. Such cross-correlations are also expected to be immune to some of the systematic effects that complicate correlation measurements internal to galaxy surveys. We present measurements and modeling of the cross-correlations between galaxy positions and galaxy lensing measured in the first three years of data from the Dark Energy Survey with CMB lensing maps derived from a combination of data from the $2500{\mathrm{deg}}^2$ SPT-SZ survey conducted with the South Pole Telescope and full-sky data from the Planck satellite. The CMB lensing maps used in this analysis have been constructed in a way that minimizes biases from the thermal Sunyaev Zel’dovich effect, making them well suited for cross-correlation studies. The total signal-to-noise of the cross-correlation measurements is 23.9 (25.7) when using a choice of angular scales optimized for a linear (nonlinear) galaxy bias model. We use the cross-correlation measurements to obtain constraints on cosmological parameters. For our fiducial galaxy sample, which consist of four bins of magnitude-selected galaxies, we find constraints of ${\mathrm{\Omega }}_{\mathrm{m}}={0.272}_{-0.052}^{+0.032}$ and $S_8\equiv {\sigma }_8\sqrt{{\mathrm{\Omega }}_{\mathrm{m}}/0.3}={0.736}_{-0.028}^{+0.032}$ (${\mathrm{\Omega }}_{\mathrm{m}}={0.245}_{-0.044}^{+0.026}$ and $S_8={0.734}_{-0.028}^{+0.035}$) when assuming linear (nonlinear) galaxy bias in our modeling. Considering only the cross-correlation of galaxy shear with CMB lensing, we find ${\mathrm{\Omega }}_{\mathrm{m}}={0.270}_{-0.061}^{+0.043}$ and $S_8={0.740}_{-0.029}^{+0.034}$. Our constraints on $S_8$ are consistent with recent cosmic shear measurements, but lower than the values preferred by primary CMB measurements from Planck.

• Received 4 April 2022
• Accepted 30 September 2022

DOI:https://doi.org/10.1103/PhysRevD.107.023530