Strings, Branes and the Search for Unification

弦、膜和对统一的追求

• 批准号: 0906222
• 负责人: Melanie Becker
• 金额: $ 105万
• 依托单位: Texas A&M Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0906222&HistoricalAwards=false
• 关键词: Strings; Branes; Search; Unification

The three researchers on this proposal propose a program investigating fundamental aspects of string theory and M-theory and their implications for particle phenomenology and cosmology. One aspect of this project deals with the construction and implications for phenomenology of flux backgrounds for heterotic strings, which they denote by torsional heterotic geometries. The heterotic string is a natural setting to construct models of particle phenomenology. However, the role played by background H-flux has not been unraveled yet, even though it may profoundly influence the 4d low-energy effective action. In this project the PIs employ a strategy to obtain the first large class of torsional heterotic geometries by explicitly constructing their metric. The number of torsional heterotic geometries turns out to be of the same order of magnitude as the number of type II flux backgrounds. The explicit examples display an N=2,1,0, supersymmetry in 4d. Flux changes the 4d phenomenology and the PIs are investigating the implications of this new strategy. They propose strategies to obtain chiral matter and novel ways to break the E8 gauge symmetry to the standard model gauge group. These backgrounds stand a much better chance of admitting tractable world-sheet descriptions compared to the type II counterparts. The precise implications of torsional geometries for algebraic geometry such as the calculation of the exact moduli space of torsional geometries, the resolution of singularities, the construction of vector bundles and ultimately three-generation models with stabilized moduli is proposed. Evidence of string theory from cosmology will be explored in terms of a brane inflation model. String theory models make predictions for gravitational radiation and lead to strong non-Gaussianities in the cosmic microwave background. Several aspects of the duality between M-theory compactifications to 4d space-time and its boundary conformal field theories (CFT) will also be explored. The research also includes a systematic construction and possible string/M-theory embedding of new supergravities in diverse dimensions, exploration of infinite dimensional symmetries, and their implications for integrability in string theory in nontrivial backgrounds. Finally, the important question of the uniqueness of string theory as a candidate for a quantum theory of gravity will be addressed in the context of 3d quantum gravity and its dual CFT. The broader impacts of the project are related to the importance of testing string theory as theory that can describe experiments. The PIs are looking for ways to understand the experimental tests for Cosmology and particle physics. In the LHC era and with new satellites becoming available, it is vital to work out the connections between physics at the Planck scale and TeV scale physics, while advancing our knowledge in string cosmology. The final goal of this project is to unravel the imprints of high-energy physics onto our 4d world. At the same time the program is expected to have a profound impact on different areas of mathematics. Two of the PIs have just written an important book on string theory and M theory with John Schwartz, one of the founders of superstring theory. All three PIs are involved in disseminating information about string theory by giving talks at workshops and conferences as well as organizing workshops. They are also involved in collaborations with mathematicians to understand the topology and geometry of string theory.

有关该建议的三名研究人员提出了一个计划，研究了弦理论和M理论的基本方面及其对粒子现象学和宇宙学的影响。该项目的一个方面涉及对杂质弦的通量背景的现象学的构建和含义，它们用扭转杂散的几何形状表示。杂种弦是构建粒子现象学模型的自然环境。但是，背景H-流量扮演的角色尚未揭示，尽管它可能会深刻影响4D低能的有效作用。在这个项目中，PI采用了一种策略，通过明确构建其指标来获得第一类大型扭转异差几何形状。事实证明，扭转杂音几何形状的数量与II型通量背景的数量相同。显式示例显示N = 2,1,0，4D中的超对称性。通量改变了4D现象学，而PI正在研究这种新策略的含义。他们提出了获取手性质和新颖方法将E8仪表对称性分解为标准模型量规组的策略。与II型对应物相比，这些背景有更好的机会承认可访问的世界地面描述。扭转几何形状对代数几何形状的确切含义，例如计算扭转几何的确切模量空间，奇异性的分辨率，载体束的构建以及最终具有稳定模量的三生模型。宇宙学的弦理论的证据将以勃雷通货膨胀模型来探讨。 弦理论模型可以预测重力辐射，并在宇宙微波背景下导致强烈的非高斯。 还将探讨M理论压缩到4D时空及其边界形式综合场理论（CFT）之间的二元性的几个方面。这项研究还包括系统的构造和可能的弦/M理论嵌入不同维度的新超级重力，无限维度对称性的探索以及它们在非平凡背景中对弦乐理论中的整合性的含义。最后，将在3D量子重力及其双重CFT的背景下解决弦理论作为量子重力理论的候选者的独特性的重要问题。 该项目的更广泛影响与测试弦理论作为可以描述实验的理论的重要性有关。 PI正在寻找了解宇宙学和粒子物理学的实验测试的方法。在LHC时代，随着新卫星的可用性，在Planck量表和TEV量表物理学上进行物理学之间的联系至关重要，同时促进了我们在弦乐宇宙学方面的知识。该项目的最终目标是将高能物理学的烙印揭示到我们的4D世界上。同时，该计划有望对数学的不同领域产生深远的影响。 PI中的两个刚刚与John Schwartz一起写了一本关于弦理论和M理论的重要书，John Schwartz是SuperString Theory的创始人之一。所有三个PI都通​​过在研讨会和会议上进行演讲以及组织研讨会来传播有关弦理论的信息。 他们还参与了与数学家的合作，以了解弦理论的拓扑和几何形状。