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Detection and characterisation of dark-matter halos by gravitational shear and flexion; constraints on the non-linear cosmic structure growth

通过引力剪切和弯曲检测和表征暗物质晕；

基本信息

批准号：
42389529
负责人：
Professor Dr. Matthias Bartelmann
金额：
--
依托单位：
Institut für Theoretische Physik
依托单位国家：
德国
项目类别：
Priority Programmes
财政年份：
2007
资助国家：
德国
起止时间：
2006-12-31 至 2011-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/42389529?language=en
关键词：
Detection characterisation dark matter halos

项目摘要

Gravitational lensing is among the most powerful tools to study dark structures in the Universe and their growth over cosmological epochs. Over the past years, the precise measurement of cosmic shear has developed impressively quickly into one of the pillars supporting the cosmological standard model. The shear traces the gravitational tidal field, i.e. second derivatives of the gravitational potential. Important information must also be contained in its third derivatives, which can conveniently be combined to form the two-component flexion. Despite its higher order, flexion has comparable or superior signal-to-noise properties compared to the shear. Its sensitivity to smaller scales in the matter distribution makes it a highly interesting and welcome tool to detect dark-matter halos and to study their internal composition, and thus to test generic predictions of the CDM cosmogony which are still controversial. We have continued our study of the shapelet technique for measuring flexion, removed several of its limitations and problems, developed a new, reliable implementation and demonstrated that it has now reached similar reliability as alternative shear measurements. We here propose to continue this programme towards a systematic calibration of shapelet measurements of the flexion, applications of flexion measurements to the detailed reconstruction of galaxy clusters, the detection of dark-matter halos and their substructures, and the study of nonlinear cosmic structure growth.

引力透镜是研究宇宙中暗结构及其在宇宙学时期的增长的最有力工具之一。在过去的几年里，宇宙剪切力的精确测量已经迅速发展成为支持宇宙学标准模型的支柱之一。剪切跟踪重力潮汐场，即重力位的二阶导数。重要的信息也必须包含在它的三阶导数中，这可以方便地组合成双分量屈曲。尽管屈曲的阶数较高，但与剪切相比，屈曲具有相当或上级的信噪比特性。它对物质分布中较小尺度的敏感性使其成为一种非常有趣和受欢迎的工具，用于探测暗物质晕并研究其内部组成，从而测试仍然有争议的CDM宇宙演化的一般预测。我们继续研究了用于测量屈曲的shapelet技术，消除了其几个局限性和问题，开发了一种新的可靠实施方案，并证明其现在已达到与替代剪切测量相似的可靠性。在这里，我们建议继续这一计划走向系统校准shapelet测量的弯曲，弯曲测量的应用程序的详细重建星系团，暗物质晕及其子结构的检测，和非线性宇宙结构的增长研究。