在进化过程中用闵可夫斯基函数对低边驱动器的拓扑和形态特征进行评价Evaluation of the Topological and Morphological Characteristics of the LSS During Evolution Process by Means of Minkowski Functionals |
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课程网址: | http://videolectures.net/nipsworkshops2011_sidorenko_evaliation/ |
主讲教师: | Irina Sidorenko |
开课单位: | 马克斯普朗克研究所 |
开课时间: | 2012-01-23 |
课程语种: | 英语 |
中文简介: | 我们利用Minkowski功能(MF)研究了由千年模拟(Springel,V.等人,2005,Nature 432,629)产生的宇宙大尺度结构(LSS)的拓扑结构。MF提供了任意结构的整体形态和拓扑特征。应用于暗物质结构的密度场,反映了LSS演化过程中的变化。我们分析了不同半径(r=1.25 mpc到r=10 mpc)的高斯滤波器在不同演化时间(z=127到z=0)平滑的模拟暗物质密度场。我们证明了大半径高斯平滑(r=10 mpc)不能正确地反映暗物质结构在演化过程中的拓扑变化,并破坏了目前宇宙中LSS的丝状结构(z=0),它仍然存在于小半径滤波器平滑的密度场中(r=1.25 mpc或r=2.5)。MPC)。LSS从宇宙早期几乎随机分布的物质到目前丝状结构的转变对应于mf_2、mf_3和mf_4相对于平均密度值的不对称性的开始和增加。 |
课程简介: | We study the topology of the cosmic Large-Scale Structures (LSS) produced by Millennium simulations (Springel , V. et al., 2005, Nature 432, 629) by means of Minkowski Functionals (MF). MF provide global morphological and topological characteristics of arbitrary structures. Applied to the density field of dark matter structure they reflect changes during time evolution of LSS. We analyse the simulated dark matter density field smoothed by Gaussian filters with different radii (from r=1.25 Mpc up to r=10 Mpc) at different evolution time (from z=127 up to z=0). We demonstrate that Gaussian smoothing with a large radius (r=10 Mpc) do not properly reflect topological changes in the dark mater structure during the evolution process and destroys filamentary structure of the LSS at present Universe (z=0), which remains present in the density field smoothed by the filters with small radii (r=1.25 Mpc or r=2.5 Mpc). Transformation of the LSS from a nearly random distribution of matter at early stage of the Universe to the filamentary structure at present time corresponds to the onset and increase of an asymmetry in MF_2, MF_3 and MF_4 with respect to the mean density value. |
关 键 词: | 拓扑结构; 闵可夫斯基函数; 高斯平滑滤波器; 平均密度值 |
课程来源: | 视频讲座网 |
最后编审: | 2020-06-01:吴雨秋(课程编辑志愿者) |
阅读次数: | 64 |