Extended and Novel Particle Sectors in String Theory

该奖项资助东北大学詹姆斯·哈尔弗森教授的研究活动。弦理论试图在一个共同的统一框架内描述物理定律，如那些支配电磁、核物理和引力的定律。弦理论的一个核心方面是，它预测了额外维度空间的存在，而这些额外维度的性质在决定粒子在该理论中如何相互作用方面发挥了很大作用。然而，事实证明，在弦理论中，这些额外维度有许多自洽的可能性。哈尔弗森教授研究的中心目标是确定一组非常常见的可能性，并分析它们对粒子物理潜在附加定律的相应预测。这一领域的研究通过在最基本的层面上促进科学的进步来服务于国家利益，在这种情况下，通过从弦理论等统一理论中为新的物理定律提供动力。该项目还将产生更广泛的重大影响。哈尔弗森教授将让博士后和学生参与他的研究，从而为初级物理学家开始他们的研究生涯提供关键培训。他还将通过NSF资助的物理TheoryNet计划向波士顿地区的高中生以及他在东北大学的本科生交流他在该领域的研究成果和相关进展。更严格地说，Halverson教授将研究弦景观，使用远离弱耦合的区域以及弦一致性条件来激发从量子场论的角度来看新颖的扩展粒子扇区(EPS)。这个项目的一个主要方面将是正式研究F理论中的非Higgsable星团，包括它们在四个维度的物理起源以及与可见和暗EPS相关的含义。他将发展新的数学，在F理论几何的背景下理解物质和纽结之间的联系，还将研究M理论的G2紧凑化中的奇异极限，以及弦一致性条件如何要求奇异物质的存在。这项工作的一个潜在贡献是发展了景观中某些EPS的典型性概念，从而为在其他物理框架中新颖或特别的模型提供了动力。

This award funds the research activities of Professor James Halverson at Northeastern University.String theory attempts to describe physical laws, such as those governing electromagnetism, nuclear physics, and gravity, in a common unified framework. One central aspect of string theory is that it predicts the existence of extra dimensions of space, and the properties of these extra dimensions play a large role in determining how particles interact in the theory. However, it turns out that there are many self-consistent possibilities for these extra dimensions in string theory. The central goal of Professor Halverson's research is to determine a set of very common possibilities and to analyze their corresponding predictions for potential additional laws of particle physics. Research in this area serves the national interest by promoting the progress of science at its most fundamental level, in this case by providing motivation for new physical laws from unified theories such as string theory. This project will also have substantial broader impacts. Professor Halverson will involve a postdoc and students in his research, and thereby provide critical training for junior physicists as they begin their research careers. He will also communicate his research results and related developments in the field to Boston-area high-school students through the NSF-funded Physics TheoryNet program, and also to his undergraduate students at Northeastern.More technically, Professor Halverson will study the string landscape, using regions away from weak coupling and also string consistency conditions to motivate extended particle sectors (EPS) that are novel from the point of view of quantum field theory. One major aspect of this project will be the formal study of non-Higgsable clusters in F-theory, including their physical origin in four dimensions and associated implications for visible and dark EPS. He will develop new mathematics to understand the connection between matter and knots in the context of F-theory geometries, and will also study singular limits in G2 compactifications of M-theory and how string consistency conditions may require the existence of exotic matter. One potential contribution of this work is to develop a notion of typicality of certain EPS in the landscape, thereby providing motivation for models that are either novel or ad hoc in other physical frameworks.