Exploration of 3D wavelet scattering transform coefficients for line-intensity mapping measurements

ABSTRACT The wavelet scattering transform (WST) has recently gained attention in the context of large-scale structure studies, being a possible generator summary statistics encapsulating non-Gaussianities beyond reach conventional power spectrum. This work examines three-dimensional solid harmonic WST line-intensity mapping measurement to be undertaken by current and proposed phases CO Mapping Array Project (COMAP). coefficients demonstrate interpretable behaviour noiseless simulations. contribution cosmological z ? 3 signal these is also detectable principle even Pathfinder phase COMAP. Using peak-patch method generate large numbers simulations incorporating observational noise, we numerically estimate covariance matrices show that careful choices hyperparameters rescaled or reduced coefficient sets are both necessary keep covariances well-conditioned. Fisher forecasts ‘shapeless’ set ?-averaged constraining can exceed spectrum alone with similar detection significance. full could improve parameter constraints over combination voxel intensity distribution, showing it uniquely encapsulates shape information about field. However, practical applications urgently require further understanding key contexts like cross-correlations.