Intrinsic ellipticity correlations between galaxies

下一代弱透镜巡天的目标是将宇宙学参数限制在百分之几的精度，特别是他们将测量暗能量状态方程参数及其时间演化到非常高的精度。为了达到这种精度，需要一个非常好的控制系统，最重要的是光度红移估计的透镜星系，特别是层析测量，和内在的椭圆相关性，模仿弱透镜信号。这些内在的排列是由相邻星系的角动量之间的相关性引起的，并已被证明会显着影响参数的估计。该项目的中心目标是通过推导高阶相关函数，提高对椭圆率对准的理解，椭圆率对准与角动量模型的大尺度结构的潮汐场有关。此外，我们的目标是调查的可行性，密度场重建使用固有的椭圆相关，这被证明是占主导地位的弱透镜诱导的低红移。

The next generation of weak lensing surveys will aim to constrain the cosmological parameters to an accuracy of a few percent, in particular they will measure the dark energy equation of state parameter and its time evolution to very high accuracy. In order to reach this accuracy, one needs a very good control of systematics, most importantly of the photometric redshift estimation of the lensed galaxies, in particular for tomographic measurements, and of intrinsic ellipticity correlations, which mimick the weak lensing signal. These intrinsic alignments are induced by the correlations between angular momenta of neighbouring galaxies and have been shown to affect the estimation of parameters significantly. The central goal of this project is to improve the understanding of ellipticity alignments, which are related to the tidal field of the large-scale structure by angular momentum models, by deriving higher-order correlation functions. Furthermore, we aim to investigate the feasibility of density field reconstructions using intrinsic ellipticity correlations, which were shown to dominate at low redshift over the weak lensing induced ones.