Speaker
Description
The lensing convergence field describing the weak lensing effect of the Cosmic Microwave Background (CMB) radiation is expected to be subject to mild deviations from Gaussianity. Accurately predicting this non-Gaussianity requires precise numerical simulations. However, simulating CMB lensing, which involves lens structures all the way back to the last scattering surface, is computationally intensive. We present a full-sky CMB lensing simulation algorithm that addresses this challenge by combining the multi-plane method with hierarchical N-body simulations using adaptive box sizes for generating lens shells. This method achieves high angular resolution (up to $\ell \sim 3000$) and full-sky coverage while maintaining manageable computational demands. Our results demonstrate that high-redshift coverage in numerical simulations, up to $z \sim 10$, is essential for capturing non-Gaussian features in the lensing field. Incorporating non-Gaussian information in the analysis improves constraints on cosmological parameters. This work provides precise predictions for non-Gaussianity in CMB lensing data, which will be important for CMB lensing analysis in future CMB experiments. Additionally, the algorithm can be adapted for use in galaxy weak lensing simulations by adjusting the source redshift, allowing for its application in a broader range of cosmological studies.
