CAREER: Towards realistic halo-scale constraints on the nature of dark matter and gravity

暗物质(DM)的性质和引力是天体物理学中最重要的悬而未决的问题之一。为了区分可能的解决方案，天体物理学家将观测到的星系分布与超级计算机模拟进行比较，超级计算机模拟在具有不同DM和引力模型的“假”宇宙中跟踪星系的形成和演化。这个研究团队将创建一个雄心勃勃的模拟套件，统一涵盖前所未有的DM和重力模型。这些模拟将公开提供，并将能够与观测调查进行详细比较，这些调查预计将在该奖项的5年寿命内发布数据，这可能会排除某些DM和重力模型。该项目还将支持指导一名博士后研究人员和一名研究生，以及探索3D打印等新工具，向广泛的学习者教授宇宙学。人们付出了巨大的努力来寻找不同的DM和引力模型的可观测印记，但不同小组的工作通常不可能相互比较，因为它们依赖于不同的宇宙学参数、星系形成物理、模拟代码和分析工具。因此，仍然不清楚哪些模型签名是健壮的，哪些是与其他模型、宇宙学或理解较少的反馈过程的签名退化的。这个项目代表了一种在小尺度上寻找独特的可观测特征的系统方法，重点是(亚)晕的密度结构、星系团的外围以及卫星星系的分布。由此产生的模拟套件在其一致性、模型的广度以及从矮小星系到星系团的质量范围方面将是独一无二的。公开可用的模拟将使无数的社区项目成为可能。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The nature of dark matter (DM) and gravity are among the foremost unsolved problems in astrophysics. To distinguish between the possible solutions, astrophysicists compare the observed distribution of galaxies to supercomputer simulations, which follow the formation and evolution of galaxies in “fake” Universes with different DM and gravity models. This team of investigators will create an ambitious simulation suite that uniformly covers an unprecedented range of DM and gravity models. The simulations will be publicly available and will enable detailed comparisons to observational surveys that are expected to release data during the 5-year lifetime of this award, potentially ruling out certain models of DM and gravity. This project will also support the mentoring of a postdoctoral researcher and a graduate student, as well as an exploration of novel tools such as 3D printing to teach cosmology to a wide range of learners. Enormous effort has been devoted to finding observable imprints of different DM and gravity models, but the work of different groups is most often impossible to inter-compare because they rely on different cosmological parameters, galaxy formation physics, simulation codes, and analysis tools. As a result, it is still unclear which model signatures are robust and which are degenerate with those of other models, cosmology, or poorly understood feedback processes. This project represents a systematic approach to searching for unique observable signatures on small scales, focusing on the density structure of (sub-)halos, the outskirts of galaxy clusters, and the distribution of satellite galaxies. The resulting simulation suite will be unique in its uniformity, its breadth of models, and its mass range from dwarf galaxies to clusters. The publicly available simulations will enable countless community projects.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.