排序方式: 共有2条查询结果,搜索用时 0 毫秒
1
1.
PeterColes 《Monthly notices of the Royal Astronomical Society》2002,330(2):421-424
The dynamical equations describing the evolution of a self-gravitating fluid can be rewritten in the form of a Schrödinger equation coupled to a Poisson equation determining the gravitational potential. This approach has a number of interesting features, many of which were pointed out in a seminal paper by Widrow & Kaiser. In particular we show that this approach yields an elegant reformulation of an idea of Jones concerning the origin of lognormal intermittency in the galaxy distribution. 相似文献
2.
The analysis of redshift surveys with fractal tools requires one to apply some form of statistical correction for galaxies lying near the geometric boundary of the sample. In this paper we compare three different methods of applying such a correction to estimates of the correlation integral in order to assess the extent to which estimates may be biased by boundary terms. We apply the corrections to illustrative examples, including a simple fractal set (Lévy flight), a random β -model, and a subset of the CfA2 Southern Cap survey. This study shows that the new 'angular' correction method we present is more generally applicable than the other methods used to date: the conventional 'capacity' correction imposes a bias towards homogeneity, and the 'deflation' method discards large-scale information, and consequently reduces the statistical usefulness of data sets. The 'angular' correction method is effective at recovering true fractal dimensions, although the extent to which boundary corrections are important depends on the form of fractal distribution assumed as well as the details of the survey geometry. We also show that the CfA2 Southern sample does not show any real evidence of a transition to homogeneity. We then revisit the IRAS PSC z survey and 'mock' PSC z catalogues made using N -body simulations of two different cosmologies. The results we obtain from the PSC z survey are not significantly affected by the form of boundary correction used, confirming that the transition from fractal to homogeneous behaviour reported by Pan & Coles is real. 相似文献
1