Exploring New Frontiers in the Dark or Invisible Universe

宇宙学为超越粒子物理学标准模型的新物理学提供了最好的证据。 为了解释我们的宇宙，新的粒子，或者对广义相对论等现有理论的关键改变是必要的。该提案旨在从理论和实验上探索和限制暗物质、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，但人们对它的粒子性质知之甚少。我们探索粒子暗物质的现象学，通过寻找在宇宙学，直接检测，或加速器的不同签名的模型。 如果暗物质是自相互作用的，与其他粒子相互作用，或者通过非热产生产生，它会以精确和可计算的方式修改宇宙学扰动的演化，并改变宇宙中物质的分布。宇宙微波背景、大尺度结构和星系内部物质的分布为暗物质粒子物理学提供了关键的实验约束。 我们将扩展和概括我现有的工作，在一整类将暗物质与相对论性粒子耦合的理论中精确预测初始暗物质的分布。使用这些预测物理自洽模拟暗物质物理可以导致强大的约束暗物质的物理。 类似的技术允许宇宙学约束其他非标准粒子相互作用，包括中微子，我们将探索此类非标准中微子相互作用的物理学。最后，该提案旨在帮助加拿大氢强度映射实验（CHIME），这是一个由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。这种奋进需要新的算法和分析来区分暗能量信号与占主导地位的前景信号的污染。我们建议继续开发技术来拒绝前景模式，并找到实用和有效的方法将实验观测值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.