Collaborative Research: Starless Dark Matter Halos as a Definitive Test of Dark Matter Models

在过去的40年里，大量的天文观测提供了压倒性的证据，表明宇宙中大约80%的质量密度是以暗物质的形式存在的。关于暗物质的主要理论认为，它是由迄今尚未发现的自然界基本粒子组成的，这些粒子比质子质量大得多，与组成地球和太阳的正常物质的相互作用非常弱，出现在元素周期表上。重要的是，主导理论？被称为冷暗物质？对暗物质在可见星系之间的空间中聚集和聚集的方式做出了具体的预测。引力透镜是一种潜在地可以探测到这些团块的技术。如果它们像预测的那样被探测到并被量化，它将提供迄今为止最令人信服的证据，证明冷暗物质的存在。如果不是，那么这将是一个重大发现，对暗物质的主导理论提出了质疑。该项目旨在对冷暗物质结构的聚集和聚集做出前所未有的准确预测，并解释正在进行的利用引力透镜作为暗物质模型测试的努力。该提案还将促进学生在高性能计算、数据分析和定量推理方面的培训，所有这些都对国家未来的经济活力至关重要。PIS还将在高中教师发展、URM推广计划和公共科学讲座上投入相当大的努力。这一提议使用了体积和分辨率无与伦比的组合的宇宙学模拟，以严格量化低质量(M107mSun)暗物质晕的性质。在标准的LCDM宇宙学模型中，这些晕被预测为没有恒星，几乎没有重子。对这种暗物质结构的引力探测将是革命性的，因为它将立即和明确地排除所有通过修改牛顿(或爱因斯坦)引力来解释观察到的质量差异的模型。它还将排除所有在这种尺度上截断功率谱的暗物质模型(例如，最流行的暖暗物质模型)。这项拟议的工作将提供充分利用即将到来的引力透镜研究所需的预测，这些研究旨在限制无恒星晕的数量和性质。这些预测依赖于高分辨率、大宇宙体积和重子物理学的包含，以适当地解释亚晕分裂、电离时的重子质量损失以及正在研究的小晕的其他动力学反馈。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。

Over the last 40 years, a large number of astronomical observations have provided overwhelming evidence that approximately 80% of the mass-density in the universe is in the form of dark matter. The leading theory for dark matter posits that it is made up of as-of-yet undiscovered elementary particles of nature, particles that are significantly more massive than the proton and have very weak interactions with normal matter of the type that makes up the earth and the sun and appears on the periodic table of elements. Importantly, the leading theory ? known as Cold Dark Matter ? makes concrete predictions for the way dark matter should be clustered and clumped in the space between visible galaxies. Gravitational lensing is a technique that can potentially detect these clumps. If they are detected and quantified as predicted it would provide the most compelling evidence yet that the Cold Dark Matter exists. If not, then this would be a major discovery that calls into question the leading theory of dark matter. This project aims to make unprecedentedly accurate predictions of the clustering and clumping of Cold Dark Matter structures and to interpret ongoing efforts to utilize gravitational lensing as a test of dark matter models. The proposal will also facilitate student training in high-performance computing, data analysis, and quantitative reasoning, all of which are vital to future economic vitality of the nation. The PIs will also devote considerable effort towards high school teacher development, URM outreach programs, and public science talks. This proposal uses cosmological simulations with an unparalleled combination of volume and resolution to rigorously quantify properties of low-mass (M 107 Msun) dark matter halos. In the standard LCDM cosmological model these halos are predicted to be starless and nearly baryon-free. Gravitational detection of such dark matter structures would be revolutionary, as it would immediately and definitively exclude all models that explain observed mass discrepancies through modifications of Newtonian (or Einsteinian) gravity. It would also rule out all models of dark matter with truncated power spectra at this scale (e.g., the most popular Warm Dark Matter models). The proposed work will provide predictions necessary to take full advantage of upcoming gravitational lensing studies aimed at constraining the number and properties of starless halos. The predictions rely on high resolution, large cosmological volumes, and the inclusion of baryonic physics to properly account for subhalo disruption, baryonic mass loss at reionzation, and other dynamical feedback on the small halos under study.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.