AN IDEAL MASS ASSIGNMENT SCHEME FOR MEASURING THE POWER SPECTRUM WITH FAST FOURIER TRANSFORMS

	AN IDEAL MASS ASSIGNMENT SCHEME FOR MEASURING THE POWER SPECTRUM WITH FAST FOURIER TRANSFORMS
	Cui, Weiguang 1,2,3; Liu, Lei1,2,3 ; Yang, Xiaohu 1,2,3; Wang, Yu 1,2,3; Feng, Longlong4 ; Springel, Volker 5
刊名	ASTROPHYSICAL JOURNAL
	2008-11-10
卷号	687 期号:2 页码:738-744
关键词	cosmology: theory large-scale structure of universe methods: data analysis methods: numerical
ISSN号	0004-637X
英文摘要	In measuring the power spectrum of the distribution of large numbers of dark matter particles in simulations, or galaxies in observations, one has to use fast Fourier transforms (FFT) for calculational efficiency. However, because of the required mass assignment onto grid points in this method, the measured power spectrum obtained with an FFT is not the true power spectrum P(k), but instead, one that is convolved with a window function vertical bar W(k)vertical bar(2) in Fourier space. In a recent paper, Jing proposed an elegant algorithm to deconvolve the sampling effects of the window function and to extract the true power spectrum, and tests using N-body simulations show that this algorithm works very well for the three most commonly used mass assignment functions, i.e., the nearest grid point, the cloud-in-cell,and the triangular-shaped cloud methods. In this paper, rather than trying to deconvolve the sampling effects of the window function, we propose to select a particular function in performing the mass assignment that can minimize these effects. An ideal window function should fulfill the following criteria: (1) compact top-hat-like support in Fourier space to minimize the sampling effects; and (2) compact support in real space to allow a fast and computationally feasible mass assignment onto grids. We find that the scale functions of Daubechies wavelet transformations are good candidates for such a purpose. Our tests using data from the Millennium Simulation show that the true power spectrum of dark matter can be accurately measured at a level better than 2% up to k 0:7k(N), without applying any deconvolution processes. The new scheme is especially valuable for measurements of higher order statistics, e. g., the bispectrum, where it can render the mass assignment effects negligible up to comparatively high k.
学科主题	Astronomy & Astrophysics
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	GALAXY REDSHIFT SURVEY ; LARGE-SCALE STRUCTURE ; DIGITAL SKY SURVEY ; MULTIRESOLUTION DECOMPOSITION ; WAVELET ANALYSIS ; IRAS GALAXIES ; CLUSTERS ; UNIVERSE ; EVOLUTION ; MATTER
收录类别	SCI
语种	英语
WOS记录号	WOS:000260566700001
公开日期	2011-12-30
内容类型	期刊论文
源URL	[http://159.226.72.40/handle/332002/1981]
专题	紫金山天文台_南极天文中心
作者单位	1.Shanghai Astron Observ, Partner Grp MPA, Shanghai 200030, Peoples R China 2.Shanghai Astron Observ, JOINGC, Shanghai 200030, Peoples R China 3.Univ Sci & Technol China, Hefei, Peoples R China 4.Acad Sinica, Purple Mt Observ, Nanjing 210008, Peoples R China 5.Max Planck Inst Astrophys, D-85748 Garching, Germany
推荐引用方式 GB/T 7714	Cui, Weiguang,Liu, Lei,Yang, Xiaohu,et al. AN IDEAL MASS ASSIGNMENT SCHEME FOR MEASURING THE POWER SPECTRUM WITH FAST FOURIER TRANSFORMS[J]. ASTROPHYSICAL JOURNAL,2008,687(2):738-744.
APA	Cui, Weiguang,Liu, Lei,Yang, Xiaohu,Wang, Yu,Feng, Longlong,&Springel, Volker.(2008).AN IDEAL MASS ASSIGNMENT SCHEME FOR MEASURING THE POWER SPECTRUM WITH FAST FOURIER TRANSFORMS.ASTROPHYSICAL JOURNAL,687(2),738-744.
MLA	Cui, Weiguang,et al."AN IDEAL MASS ASSIGNMENT SCHEME FOR MEASURING THE POWER SPECTRUM WITH FAST FOURIER TRANSFORMS".ASTROPHYSICAL JOURNAL 687.2(2008):738-744.