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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暗结构及其在宇宙学时代的增长的最强大工具之一。在过去的几年里，宇宙剪切力的精确测量已经令人印象深刻地迅速发展成为支持宇宙学标准模型的支柱之一。剪切力追踪引力潮汐场，即引力势的二阶导数。重要信息还必须包含在其三阶导数中，可以方便地组合起来形成双分量屈曲。尽管其阶数较高，但与剪切相比，弯曲具有可比或更好的信噪比特性。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，用于检测暗物质晕并研究其内部组成，从而测试仍然存在争议的 CDM 宇宙起源的一般预测。我们继续研究用于测量屈曲的 shapelet 技术，消除了它的一些局限性和问题，开发了一种新的、可靠的实现方式，并证明它现在已经达到了与替代剪切测量类似的可靠性。我们在此建议继续该计划，以系统校准弯曲的形状波测量，将弯曲测量应用于星系团的详细重建，暗物质晕及其子结构的检测，以及非线性宇宙结构生长的研究。