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arXiv 1306.2737astro-ph.CO
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在斯隆数字巡天类星体目录中寻找非环形拓扑透镜

A search for nontoroidal topological lensing in the Sloan Digital Sky Survey quasar catalog

Hirokazu Fujii, Yuzuru Yoshii

摘要:

利用斯隆数字巡天(SDSS)的高红移($z \geq 4$)类星体的分布,对具有多连通拓扑结构的平坦空间模型进行了检验。当紧凑维度的尺寸小于观测到的宇宙时,拓扑透镜现象就会发生,其中单个物体的多个图像(鬼像)被观测到。我们改进了最近推出的方法来识别鬼图像通过四点统计。我们的方法是有效的任何17个多连接的平面模型,包括nontoroial的螺旋运动或滑翔反射紧致。将该方法应用于数据揭示了由六转螺旋运动引起的拓扑透镜的一种可能的情况,然而,仅通过该测试,它与简单连接模型一致。此外,模拟表明,我们不能排除其他空间模型,尽管没有他们的签名。这种不确定性主要来源于SDSS在南银帽的不均匀覆盖,未来的宽视场光谱巡天将改善这种情况。

英文摘要:

Flat space models with multiply connected topology, which have compact dimensions, are tested against the distribution of high-redshift ($z \geq 4$) quasars of the Sloan Digital Sky Survey (SDSS). When the compact dimensions are smaller in size than the observed universe, topological lensing occurs, in which multiple images of single objects (ghost images) are observed. We improve on the recently introduced method to identify ghost images by means of four-point statistics. Our method is valid for any of the 17 multiply connected flat models, including nontoroial ones that are compactified by screw motions or glide reflection. Applying the method to the data revealed one possible case of topological lensing caused by sixth-turn screw motion, however, it is consistent with the simply connected model by this test alone. Moreover, simulations suggest that we cannot exclude the other space models despite the absence of their signatures. This uncertainty mainly originates from the patchy coverage of SDSS in the South Galactic cap, and the situation will be improved by future wide-field spectroscopic surveys.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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