Title: Topology and geometry of the dark matter web: a multistream view Show Chinese title

Title: 暗物质网的拓扑与几何：多流视角

Abstract: Topological connections in the single-streaming voids and multistreaming filaments and walls reveal a cosmic web structure different from traditional mass density fields. A single void structure not only percolates the multistream field in all the directions, but also occupies over 99 per cent of all the single-streaming regions. Sub-grid analyses on scales smaller than simulation resolution reveal tiny pockets of voids that are isolated by membranes of the structure. For the multistreaming excursion sets, the percolating structure is significantly thinner than the filaments in over-density excursion approach. Hessian eigenvalues of the multistream field are used as local geometrical indicators of dark matter structures. Single-streaming regions have most of the zero eigenvalues. Parameter-free conditions on the eigenvalues in the multistream region may be used to delineate primitive geometries with concavities corresponding to filaments, walls and haloes. Show Chinese abstract

Abstract: 宇宙网结构中的单流空洞和多流丝状结构及墙结构的拓扑连接显示出与传统质量密度场不同的宇宙网结构。 一个单一的空洞结构不仅在所有方向上渗透多流场，还占据了所有单流区域的99%以上。 对小于模拟分辨率尺度的亚网格分析揭示了由结构膜隔离的微小空洞区域。 对于多流跳跃集，渗透结构比高密度跳跃方法中的丝状结构显著更薄。 多流场的Hessian特征值被用作暗物质结构的局部几何指标。 单流区域大部分具有零特征值。 多流区域中特征值的无参数条件可用于描绘具有凹陷的原始几何结构，这些凹陷对应于丝状结构、墙和晕。