The Origin of Matter in the Universe: Nonequilibrium Field Theory and Inflationary Cosmology

宇宙中物质的起源：非平衡场论和暴胀宇宙学

• 批准号: 0653341
• 负责人: Marcelo Gleiser
• 金额: $ 1.5万
• 依托单位: Dartmouth College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0653341&HistoricalAwards=false
• 关键词: Origin; Matter; Universe; Nonequilibrium; Field

One of the greatest challenges of modern cosmology and particle physics is to explain the origin of matter in the Universe. How did the matter that makes galaxies, stars, and ultimately living beings originate in the primeval fireball described by the Big Bang model? Once the ingredients are there the leptons, quarks, and gauge fields comprising the Standard Model of particle physics Big Bang cosmology is very successful at explaining the formation of the first light nuclei and atoms. The challenge lies in understanding the mechanisms responsible for generating the particles of the Standard Model themselves: their origin and the ubiquitous excess of matter over antimatter. Observations firmly support the notion that the early Universe underwent a short period of superluminal (exponential) expansion known as inflation. The origin of matter is traced to the end of this inflationary era, when the primordial field that drives inflation transfers its energy into matter fields. This transfer is dramatic: it effectively models the hot Big Bang and is believed to have occurred in at least two phases, known as preheating and reheating. The goal of this proposal is to address both the origin of matter and its excess over antimatter as inflation transitions into the hot Big Bang model. The PI plans to analyze in detail the nonperturbative dynamics of the preheating and reheating stages for a variety of models, using analytical and numerical techniques of nonequilibrium field theory. Based on this analysis, the PI hopes to propose several observational consequences of pre/reheating for different models, including: the number of e-folds or efficacy of the inflationary phase; the generation of net baryon number; and the production of a stochastic background of gravitational waves.

现代宇宙学和粒子物理学的最大挑战之一是解释宇宙中物质的起源。构成星系、恒星和最终生命的物质是如何起源于大爆炸模型所描述的原始火球的？一旦构成粒子物理学标准模型的轻子、夸克和规范场都具备了，大爆炸宇宙学在解释第一个轻原子核和原子的形成方面就非常成功了。挑战在于理解产生标准模型粒子本身的机制：它们的起源以及物质对反物质的普遍过剩。观测结果坚定地支持了早期宇宙经历了一段短时间的超光速（指数）膨胀的观点，称为暴胀。物质的起源可以追溯到这个膨胀时代的结束，当驱动膨胀的原始场将其能量转移到物质场时。这种转移是戏剧性的：它有效地模拟了热大爆炸，并被认为至少发生在两个阶段，即预热和再加热。 这个提议的目标是解决物质的起源以及随着暴胀过渡到热大爆炸模型，物质超过反物质的问题。PI计划使用非平衡场理论的分析和数值技术，详细分析各种模型的预热和再加热阶段的非微扰动力学。基于这一分析，PI希望提出不同模型的预/再加热的几个观测结果，包括：e折叠的数量或暴胀阶段的功效;净重子数的产生;以及引力波随机背景的产生。