Gravitational lensing as a key probe to understand the cosmic acceleration

在接下来的十年里，大型星系调查，如欧几里得、LSST和DESI将开始收集数据，从而能够以更高的精度确定关键的宇宙学参数，并将不同的宇宙学模型相互区分开来。这些也将阐明关于加速宇宙膨胀的性质的具有挑战性的基本问题--它是由于某些暗能量成分还是重力的修正。前两项调查将提供极好的弱引力透镜数据，这是测试宇宙加速模型的关键探测器之一。这个项目将主要探索不同理论模型对透镜观测的预测，以及它们如何以及如何被用来约束模型。它将依靠大型高分辨率数值模拟来进行模型预测，并提高对关键观测数据背后的物理学的理解。其中很大一部分将致力于开发新的方法，这些方法最适合于在给定预期数据的情况下测试模型。也有机会将透镜探测器与星系团的探测器(来自欧几里德和DESI)结合起来，以改善模型约束。

In the next decade, large galaxy surveys such as Euclid, LSST and DESI will start to collect data, allowing key cosmological parameters to be determined with much higher precision and different cosmological models to be distinguished from each other. These will also shed light on the challenging fundamental question about the nature of the accelerated cosmic expansion - whether it is due to some dark energy component or a modification to gravity. The first two of these surveys will provide excellent data of weak gravitational lensing, which is one of the key probes to test models for the cosmic acceleration. This project will mainly explore the predictions of lensing observables by the different theoretical models, and how and how well they can be used to constrain models. It will rely on large high-resolution numerical simulations for model predictions and to improve the understanding of the physics underlying key observables. A substantial part of it will be devoted to developing novel methods that are best tailored for testing models given the expected data. There is also the opportunity to combine lensing probes with probes of galaxy clustering (from Euclid and DESI) to improve model constraints.