1995/09/06 by Jesus Pando, Jesús Pando, Pando, Jesus +3
Computer Science · Earth and Planetary Sciences · Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #Image and Signal Denoising Methods #NMR spectroscopy and applications #Seismic Imaging and Inversion Techniques #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9509032
30 pages, 9 figures, in compressed uuencoded postscript file
arxiv created 1995/09/06 · openalex publication_date 1995/09/06 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
A method for measuring the spectrum of a density field by a discrete wavelet space-scale decomposition (SSD) has been studied. We show how the power spectrum can effectively be described by the father function coefficients (FFC) of the wavelet SSD. We demonstrate that the features of the spectrum, such as the magnitude, the index of a power law, and the typical scales, can be determined with high precision by the FFC reconstructed spectrum. This method does not require the mean density, which normally is poorly determined. The problem of the complex geometry of observed samples can also be easily solved because the basis are always orthogonal, regardless the geometry of the samples. Using this method, we examine the spectra inferred from Lyα forests of both simulated and real samples. We find that 1.) the magnitude of the 1-D spectra is significantly dfferent froma Poisson process; 2) the 1-d spectra are flat on scales less than 5 h-1 Mpc, and increase slowly at larger ranges; 3.) the reconstructed 3-D spectra have about the same power as the COBE normalized linear spectrum of the SCDM model on scales less than 40 h-1 Mpc, but is larger than the SCDM model on scales larger than 40 h-1 Mpc; 4) the magnitudes of high redshift (z>2.51) spectra generally are larger than those of low redshift (z<2.51).