Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Non-Gaussianity and the recovery of the mass power spectrum from the
  Ly$\alpha$ forest   We investigate the effect of non-Gaussianity on the reconstruction of the
initial mass field from the Ly$\alpha$ forest. We show that the transmitted
flux of QSO absorption spectra are highly non-Gaussian in terms of the
statistics, the kurtosis spectrum and scale-scale correlation. These
non-Gaussianities can not be completely removed by the conventional algorithm
of Gaussianization, and the scale-scale correlations are largely retained in
the mass field recovered by the Gaussian mapping. Therefore, the mass power
spectrum recovered by the conventional algorithm is systematically lower than
the initial mass spectrum on scales at which the local scale-scale correlation
is substantial. To reduce the non-Gaussian contamination, we present two
methods. The first is to perform the Gaussianization scale-by-scale using the
discrete wavelet transform (DWT) decomposition. We show that the non-Gaussian
features of the Ly$\alpha$ forest basically will no longer exist in the
scale-by-scale Gaussianized mass field. The second method is to choose a proper
orthonormal basis (representation) to suppress the effect of the non-Gaussian
correlations. In the quasilinear regime of cosmic structure formation, the DWT
power spectrum is efficient for suppressing the non-Gaussian contamination.
These two methods significantly improve the recovery of the mass power spectrum
from the Ly$\alpha$ forest.

22
The categories of this paper are: chao-dyn
23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th
16
The categories of this paper are: stat
4
The categories of this paper are: cond-mat