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

暗物质（DM）和引力的性质是天体物理学中最重要的未解决问题之一。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了比较，超级计算机模拟遵循了具有不同DM和重力模型的“假”宇宙中星系的形成和演化。这组研究人员将创建一个雄心勃勃的模拟套件，统一覆盖DM和重力模型的前所未有的范围。模拟结果将公开，并将与观测调查进行详细比较，这些观测调查预计将在该合同的5年寿命期内发布数据，可能会排除某些DM和重力模型。该项目还将支持对一名博士后研究员和一名研究生的指导，以及对3D打印等新工具的探索，以向广泛的学习者教授宇宙学。人们已经付出了巨大的努力来寻找不同DM和重力模型的可观测印记，但不同小组的工作往往不可能相互比较，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，目前仍不清楚哪些模型签名是鲁棒的，哪些是与其他模型、宇宙学或不太了解的反馈过程的签名一起退化的。该项目代表了一种在小尺度上寻找独特可观测特征的系统方法，重点关注（亚）晕的密度结构、星系团的外围和卫星星系的分布。由此产生的模拟套件在其均匀性，模型的广度以及从矮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。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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.