Numerical investigation of non-Gaussianities in the phase and modulus of density Fourier modes

• DOI: 10.1093/mnras/stac1454
• Publication Date: 2022-05-31T22:43:37Z
• Authors: Jian Qin; Jun Pan; Yu Yu; Pengjie Zhang
• Keywords: 0303 health sciences; 03 medical and health sciences; Cosmology and Nongalactic Astrophysics (astro-ph.CO); FOS: Physical sciences; Astrophysics - Cosmology and Nongalactic Astrophysics

We numerically investigate non-Gaussianities in the late-time cosmological density field Fourier space. explore various statistics, including two-point and three-point probability distribution function (PDF) of phase modulus, two \& correlation modulus. detect significant non-Gaussianity for certain configurations. compare simulation results with theoretical expansion series \citet{2007ApJS..170....1M}. find that $\mathcal{O}(V^{-1/2})$ order term alone is sufficiently accurate to describe all measured not only PDFs, but also correlations. phase-modulus cross-correlation contributes $\sim 50\%$ bispectrum, further verifying accuracy prediction. This work demonstrates cosmic simpler space, may facilitate data analysis era precision cosmology.