Researchers have presented a hybrid method for reconstructing the primordial density from late-time halos and galaxies.
The method involves applying standard Baryon Acoustic Oscillation (BAO) reconstruction to recover large-scale features in the primordial density field.
A deep learning model is trained to learn small-scale corrections on partitioned subgrids of the full volume.
The approach significantly improves the reconstruction cross-correlation coefficient with the true initial density field and enables scaling to large survey volumes.