EAPSI: Toward Cosmic Expansion in the Framework of Supergravity Theory

EAPSI：超引力理论框架下的宇宙膨胀

• 批准号: 1614289
• 负责人: Chien-I Chiang
• 金额: $ 0.54万
• 依托单位: Chiang Chien-I
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-15 至 2017-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1614289&HistoricalAwards=false
• 关键词: EAPSI; Toward; Cosmic; Expansion; Framework

Due to the attractive nature of gravitational interaction, one would expect that our universe is expanding at a decreasing rate. Nevertheless, observations have shown that our universe is undergoing accelerating expansion at present era, and there is much evidence to indicate that a much more rapid expansion occurred in the primordial universe. Even though many phenomenological models have been proposed, the physical origin behind these mechanism is yet unknown. In particular, what kind of particles is responsible for the expansion? Is it possible to accommodate these particles with all other particles that have been discovered so far under a unified theoretical framework? With Prof. Hitoshi Murayama, a leading expert on supersymmetry, supergravity and particle physics cosmology, and with other potential collaborators at Kavli Institute for the Physics and Mathematics of the Universe at Tokyo, Japan, the awardee will attempt to extend our understanding of these fundamental questions under the theoretical framework of supersymmetry, which is a potential candidate that can unify all known interactions in particle physics.The accelerating expansion of our universe at current the era is often attributed to an exotic form of particle/field called dark energy. From the phenomenology point of view, a scalar field with a sufficiently flat potential, named quintessence, could describe dark energy. In this project we aim to construct a quintessence dark energy model that couples to the supersymmetric Standard Model of particle physics, in the framework of supergravity. When combining quintessence model with supersymmetric model of particle physics, generically the flat potential of the quintessence will be spoiled by the supersymmetry breaking. We therefore consider a form of Kahler potential that sequesters the particle physics and quintessence sector, inspired by the brane-world scenario. We will then attempt to build a model based on this and investigate various observational constraints. This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Japan Society for the Promotion of Science.

由于引力相互作用的吸引性质，人们会认为我们的宇宙正在以递减的速度膨胀。然而，观测表明，我们的宇宙正在经历加速膨胀，目前有很多证据表明，在原始宇宙中发生了更快的膨胀。尽管已经提出了许多唯象模型，但这些机制背后的物理起源仍然是未知的。 特别是，什么样的粒子负责膨胀？在一个统一的理论框架下，有没有可能把这些粒子和迄今为止发现的所有其他粒子放在一起？获奖者将与日本东京Kavli宇宙物理与数学研究所的超对称、超引力和粒子物理学宇宙学方面的顶尖专家村山仁教授，以及其他潜在的合作者一起，尝试在超对称的理论框架下扩展我们对这些基本问题的理解，这是一个潜在的候选者，可以统一粒子物理学中所有已知的相互作用。我们的宇宙在当前时代的加速膨胀通常被归因于一种被称为暗能量的粒子/场的奇异形式。从唯象学的观点来看，一个具有足够平坦势的标量场（称为quintessence）可以描述暗能量。在这个项目中，我们的目标是在超引力的框架下构建一个与粒子物理学的超对称标准模型耦合的经典暗能量模型。在将精粹模型与粒子物理的超对称模型相结合时，超对称破缺一般会破坏精粹模型的平势。因此，我们考虑一种形式的卡勒潜力，隔离粒子物理和精华部门，灵感来自膜世界的情况。然后，我们将尝试在此基础上建立一个模型，并研究各种观测约束。东亚和太平洋夏季研究所计划下的这个奖项支持美国研究生的夏季研究，由NSF和日本科学促进会共同资助。