论文标题
星系分布作为分形系统
Galaxy Distributions as Fractal Systems
论文作者
论文摘要
本文讨论了包含近一百万个物体的大型星系分布样品是否可以被描述为分形系统。 Teles等人进行的分析。 （2021; arxiv：2012.07164）在Ultravista DR1调查中，此处扩展到Splash and Cosmos2015目录，因此在研究样品中添加了750K新的星系，并带有测量的红移。具有$ h_0 =（70 \ pm5）$ km/s/mpc的标准$λ$ CDM宇宙学和将这些星系发射描述为具有尺寸$ D $的单分形系统所需的数字密度工具。我们使用光度距离$ d_l $，红移距离$ d_z $和星系区域距离（横向comoving距离）$ d_g $作为相对论距离定义，以redshift间隔$ 0.1 \ le z \ le4 $以k-bandute jembolute limate限制的量子限制为redshift间隔$ 0.1 \ le z \ le4 $。类似于Teles等人的发现。 （2021; arxiv：2012.07164），结果显示了两个连续的红移量表，其中星系分布数据以单分形结构的形式行为。对于$ z <1 $，我们发现$ d = 1.00 \ pm0.12 $用于飞溅星系，$ d = 1,39 \ pm0.19 $ for cosmos2015。对于$ 1 \ le z \ le4 $，我们分别找到$ d = 0.83^{+0.36} _ { - 0.37} $和$ d = 0.54^{+0.27} _ { - 0.26} $。在假定的哈勃恒定不确定性下，这些结果被证实是可靠的。在两项调查中考虑蓝色星系子样本的计算表明，蓝色星系的分形维度基本上没有变化，但是红色星系的分形尺寸主要变为较小的值，这意味着$ d $可以看作是宇宙中物体分布的更固有的属性，因此可以将工具凹陷用作工具的不同配置。所有结果证实了数十年来的理论预测，即$ z> 1 $的分形维度下降。
This paper discusses if large scale galaxy distribution samples containing almost one million objects can be characterized as fractal systems. The analysis performed by Teles et al. (2021; arXiv:2012.07164) on the UltraVISTA DR1 survey is extended here to the SPLASH and COSMOS2015 catalogs, hence adding 750k new galaxies with measured redshifts to the studied samples. The standard $Λ$CDM cosmology having $H_0=(70\pm5)$ km/s/Mpc and number density tools required for describing these galaxy distributions as single fractal systems with dimension $D$ are adopted. We use the luminosity distance $d_L$, redshift distance $d_z$ and galaxy area distance (transverse comoving distance) $d_G$ as relativistic distance definitions to derive galaxy number densities in the redshift interval $0.1\le z\le4$ at volume limited subsamples defined by absolute magnitudes in the K-band. Similar to the findings of Teles et al. (2021; arXiv:2012.07164), the results show two consecutive redshift scales where galaxy distribution data behave as single fractal structures. For $z<1$ we found $D=1.00\pm0.12$ for the SPLASH galaxies, and $D=1,39\pm0.19$ for the COSMOS2015. For $1\le z\le4$ we respectively found $D=0.83^{+0.36}_{-0.37}$ and $D=0.54^{+0.27}_{-0.26}$. These results were verified to be robust under the assumed Hubble constant uncertainty. Calculations considering blue and red galaxies subsamples in both surveys showed that the fractal dimensions of blue galaxies as basically unchanged, but the ones for the red galaxies changed mostly to smaller values, meaning that $D$ may be seen as a more intrinsic property of the distribution of objects in the Universe, therefore allowing for the fractal dimension to be used as a tool to study different populations of galaxies. All results confirm the decades old theoretical prediction of a decrease in the fractal dimension for $z>1$.
