Exploring New Frontiers in the Dark or Invisible Universe

宇宙学为超越粒子物理标准模型的新物理学提供了最好的证据。要解释我们的宇宙，新的粒子或对广义相对论等既定理论的关键改变是必要的。这项提议旨在从理论和实验上探索和约束暗物质、暗能量、中微子和其他几乎不可见的粒子的物理学。暗物质的丰度是宇宙中正常原子的五倍，但人们对其粒子性质知之甚少。我们通过寻找在宇宙学、直接探测或加速器中具有不同特征的模型来探索粒子暗物质的现象学。如果暗物质是自我相互作用的，与其他粒子相互作用，或者是通过非热产生产生的，它以精确和可计算的方式改变了宇宙微扰的演化，并改变了物质在宇宙中的分布。CMB、大尺度结构和星系内物质的分布为暗物质粒子物理提供了关键的实验约束。我们将扩展和概括我现有的工作，以便在一整类将暗物质与相对论粒子耦合的理论中对初始暗物质分布做出精确预测。使用这些预测，可以对暗物质物理进行物理上的自洽模拟，从而对暗物质物理产生强有力的约束。类似的技术允许宇宙学限制其他非标准粒子相互作用，包括中微子，我们将探索这种非标准中微子相互作用的物理学。最后，这项提议旨在帮助加拿大氢强度映射实验(CHME)，这是一项由CFI资助的暗能量实验，旨在测量暗能量开始主导膨胀时宇宙的膨胀率。这项工作需要新的算法和分析来区分暗能量信号和主要前景信号的污染。我们建议继续开发拒绝前景模式的技术，并找到实用和有效的方法将实验观测数据与暗能量或修正引力的理论模型联系起来。

Cosmology gives our best evidence for new physics beyond the standard model of particle physics. To explain our Universe new particles, or key changes to established theories like general relativity, are necessary. This proposal aims to explore and constrain, theoretically and experimentally, the physics of dark matter, dark energy, neutrinos, and other nearly invisible particles. Dark matter is five times more abundant than the normal atoms in the Universe but very little is known about its particle properties. We explore the phenomenology of particle dark matter by searching for models with distinct signatures in cosmology, direct detection, or accelerators. If dark matter is self-interacting, interacts with other particles, or originates via non-thermal production it modifies the evolution of cosmological perturbations in precise and calculable ways and alters the distribution of matter in the Universe. The CMB, large-scale structure, and the distribution of matter inside galaxies provide key experimental constraints on dark-matter particle physics. We will extend and generalize my existing work to make precise predictions of the initial dark matter distribution in a whole class of theories that couple dark matter to relativistic particles. Using these predictions physically self-consistent simulations of dark-matter physics can be made resulting in robust constraints on the physics of dark matter. Similar techniques allows cosmology to constrain other non-standard particle interactions, including neutrinos, and we will explore the physics of such non-standard neutrino interactions. Finally, this proposal aims to work in aide of the Canadian Hydrogen Intensity Mapping Experiment (CHIME), a CFI-funded dark energy experiment designed to measure the expansion rate of the Universe at the time dark energy started to dominate expansion. This endeavor requires novel algorithms and analysis to distinguish the dark energy signal from contamination by the dominant foreground signals. We propose to continue to develop techniques to reject foreground modes and find practical and efficient ways to connect experimental observables to theoretical models of dark energy or modified gravity.