The Dark Matter Universe

暗物质宇宙

• 批准号: RGPIN-2015-04976
• 负责人: Tulin, Sean
• 金额: $ 2.4万
• 依托单位: York University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=667263
• 关键词: Dark; Matter; Universe

Now that the Higgs boson - the final piece of the Standard Model of particle physics - has been discovered, particle physicists are turning to the cosmos to inspire the next great discoveries. The existence of dark matter is one of the Universe's greatest mysteries. Within a galaxy, all the visible matter - the stars and interstellar gas - are made from atoms, and yet atomic matter represents only 15%, on average, of the total mass of a galaxy. The remaining 85% is dark matter. Dark matter's presence in the Universe provides the cosmic foundation for galaxies and stars to form. However, its particle physics properties remains as yet unknown.******Dr. Tulin's research will provide a new direction in the quest to identify the dark matter particle. He proposes that galaxies and clusters of galaxies may be used as cosmic particle colliders to discover dark matter's elusive nature. This idea is similar in spirit to Rutherford's famous gold foil experiment: by studying the energy (and angular) dependence of alpha-particle scattering, the particle physics structure of the atom was discovered, being governed by the electromagnetic force.*******The same experiment can be done with dark matter in galaxies and galaxy clusters. Dark matter particles may scatter with other dark matter particles in a galaxy, which changes the how they are distributed, which in turn influences the motions of stars and gas that trace the dark matter particles' gravity. Moreover, different astrophysical scales, from the smallest dwarf galaxies to the largest clusters, have dark matter particles at different energies (with larger objects corresponding to larger energies). Therefore, combining observations from dwarfs to clusters is equivalent to tuning the dark matter "collider" to different energies. From this combination of astrophysical measurements, the properties of dark matter - such as its mass and the nature of its particle interactions - can be discovered.*******Although there is no guarantee that dark matter has a scattering interaction in galaxies, observations of dwarf galaxies, low surface brightness spiral galaxies, and galaxy clusters suggest that their structure is incompatible with forming by the gravitational collapse of dark matter particles that have no particle interactions. Moreover, the same particle physics giving a scattering interaction can also explain why dark matter exists in the Universe today (that is, how it was produced and why it is stable).*******Dr. Tulin's research will provide a theoretical framework, based on statistical mechanics for dark matter particles, for extracting microscopic dark matter properties from macroscopic observations of stellar and gas dynamics. He will explore the particle physics implications for dark matter and propose new models that can be connected to astrophysical observations, as well as address complementarity with searches for dark matter and other dark particles in laboratory experiments.*** **

既然希格斯玻色子--粒子物理学标准模型的最后一块--已经被发现，粒子物理学家们正转向宇宙，以激发下一个伟大的发现。暗物质的存在是宇宙中最大的谜团之一。在一个星系中，所有可见的物质--恒星和星际气体--都是由原子组成的，然而原子物质平均只占星系总质量的15%。剩下的85%是暗物质。 暗物质在宇宙中的存在为星系和恒星的形成提供了宇宙基础。 然而，它的粒子物理性质仍然未知。图林博士的研究将为寻找暗物质粒子提供一个新的方向。 他提出星系和星系团可以作为宇宙粒子对撞机来发现暗物质难以捉摸的本质。 这个想法在精神上类似于卢瑟福著名的金箔实验：通过研究α粒子散射的能量（和角度）依赖性，发现了原子的粒子物理结构，由电磁力控制。同样的实验也可以用星系和星系团中的暗物质来做。 暗物质粒子可能会与星系中的其他暗物质粒子一起散射，这会改变它们的分布方式，进而影响跟踪暗物质粒子引力的恒星和气体的运动。 此外，不同的天体物理尺度，从最小的矮星系到最大的星系团，都有不同能量的暗物质粒子（较大的物体对应较大的能量）。 因此，将从矮星到星团的观测结果结合起来，相当于将暗物质“对撞机”调到不同的能量。 从这些天体物理测量的组合中，可以发现暗物质的性质-例如它的质量和粒子相互作用的性质。虽然不能保证暗物质在星系中有散射相互作用，但对矮星系、低表面亮度螺旋星系和星系团的观测表明，它们的结构与没有粒子相互作用的暗物质粒子的引力坍缩不相容。 此外，给出散射相互作用的粒子物理学也可以解释为什么暗物质存在于今天的宇宙中（也就是说，它是如何产生的，为什么它是稳定的）。Tulin博士的研究将提供一个基于暗物质粒子统计力学的理论框架，用于从恒星和气体动力学的宏观观测中提取微观暗物质特性。 他将探索粒子物理学对暗物质的影响，并提出可以与天体物理学观测相关联的新模型，以及在实验室实验中寻找暗物质和其他暗粒子的互补性。 **