Particles, Fields and Spacetime

粒子、场和时空

• 批准号: ST/T000708/1
• 负责人: Simon Ross
• 金额: $ 140.67万
• 依托单位: Durham University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FT000708%2F1
• 关键词: Particles; Fields; Spacetime

All matter in the universe and the fundamental forces apart from gravity appear to be well described by particle theories, in which the fundamental components of matter are pointlike particles, which interact by exchanging other kinds of particles. Quantum field theory is the mathematical language describing these particle theories; the particles describing forces are described by a class of theories called gauge theories. A practical understanding of quantum field theory, which enables us to do calculations in many circumstances of interest, was constructed more than fifty years ago; however we still do not have a complete understanding of the structures implicit in quantum field theory, and recent work has opened up radically different approaches to doing calculations. It has been understood that certain gauge theories have additional previously unsuspected symmetries, which explain the mysterious simplicity of some computational results. This has been developed to obtain more efficient calculational techniques for increasingly general questions. In an independent line, a symmetry called conformal symmetry has been newly exploited to constrain the particle content and interactions of theories with this symmetry. We aim to develop these tools further and bring them together, leading to a deeper understanding of the calculation of interactions of particles in the vacuum. We will also study the theory in situations with finite density, classifying phases of matter. Symmetries play an important role here, and the breaking of symmetries by quantum effects, referred to as anomalies, provides powerful constraints on the phase structure.It appears we need to go beyond quantum field theory to include gravity. The leading candidate for this extension is string theory, which is based on the idea that the particles are actually one-dimensional loops of string, with the interactions described by smooth surfaces connecting different strings. Work on string theory has led to the discovery that some quantum field theories can be related to string theories in a space with more dimensions; this is referred to as holography. Some difficult questions in the field theory can be mapped to simpler questions in the higher-dimensional space. This also provides a new perspective on string theory, which can be used to deepen our understanding of gravity. We are studying the application of these techniques to field theories used to study interesting new phases of matter, and we are exploring the role of intrinsically quantum mechanical features of the field theory in the emergence of the higher-dimensional geometry. Cosmology is the study of the universe as a whole. The overall geometry of the universe is expanding on large scales. In the very early universe, there appears to have been a period of exponential expansion, called inflation. We are interested in the behaviour of quantum fields during this inflationary period, which we will investigate using an approach called stochastic inflation. We will also apply holographic methods to the description of the very early universe, enabling us to apply well-developed field theory tools to inflation. Black holes can be produced in the very early universe from fluctuations of the density of matter; we will study the formation and dynamics of these primordial black holes. These may be interesting as candidates for dark matter, a kind of matter required to explain observations of the large-scale dynamics in the universe today.

宇宙中的所有物质和除了引力之外的基本力似乎都可以用粒子理论很好地描述，在粒子理论中，物质的基本成分是点状粒子，它们通过交换其他种类的粒子而相互作用。量子场论是描述这些粒子理论的数学语言;描述力的粒子由一类称为规范理论的理论描述。对量子场论的实际理解，使我们能够在许多感兴趣的情况下进行计算，是在50多年前建立的;然而，我们仍然没有完全理解量子场论中隐含的结构，最近的工作开辟了完全不同的计算方法。人们已经知道，某些规范理论具有以前未曾想到的额外对称性，这解释了某些计算结果的神秘简单性。这是为了获得更有效的计算技术，越来越普遍的问题。在一条独立的线上，一种叫做共形对称的对称性被新利用来限制粒子的含量和具有这种对称性的理论的相互作用。我们的目标是进一步开发这些工具，并将它们结合在一起，从而更深入地了解真空中粒子相互作用的计算。我们还将研究有限密度情况下的理论，对物质的相进行分类。对称性在这里扮演着重要的角色，量子效应对对称性的破坏，被称为反常，对相结构提供了强有力的约束。看来我们需要超越量子场论，把引力也包括在内。这个扩展的主要候选者是弦理论，它基于这样的想法，即粒子实际上是一维的弦环，相互作用由连接不同弦的光滑表面描述。弦理论的研究发现，某些量子场论可以在更多维的空间中与弦理论联系起来;这被称为全息术。场论中的一些困难问题可以映射到高维空间中的简单问题。这也为弦理论提供了一个新的视角，可以用来加深我们对引力的理解。我们正在研究这些技术的应用领域的理论，用来研究有趣的新阶段的问题，我们正在探索的作用，内在的量子力学功能的场论中出现的高维几何。宇宙学是研究整个宇宙的学科。宇宙的整体几何形状在大尺度上膨胀。在非常早期的宇宙中，似乎有一个指数膨胀的时期，称为通货膨胀。我们感兴趣的量子场的行为在这个暴胀期间，我们将使用一种称为随机暴胀的方法进行调查。我们还将应用全息方法来描述非常早期的宇宙，使我们能够将成熟的场论工具应用于暴胀。黑洞可以在非常早期的宇宙中从物质密度的波动中产生;我们将研究这些原始黑洞的形成和动力学。作为暗物质的候选者，这些物质可能很有趣，暗物质是解释当今宇宙大规模动力学观测所需的一种物质。

项目成果

Towards the Virasoro-Shapiro amplitude in AdS5×S5

AdS5àS5 中的 Virasoro-Shapiro 振幅

• DOI: 10.1007/jhep04(2021)237
• 发表时间: 2021
• 期刊: Journal of High Energy Physics
• 影响因子: 5.4
• 作者: Abl T

Multikink scattering in the ? 6 model revisited

多扭结散射？

• DOI: 10.1103/physrevd.106.125003
• 发表时间: 2022
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Adam C

Multikink scattering in the $?^6$ model revisited

重新审视 $?^6$ 模型中的多扭结散射

• DOI: 10.48550/arxiv.2209.08849
• 发表时间: 2022
• 作者: Adam C

Magnetic quivers from brane webs with O7+-planes

来自带有 O7 平面的膜网的磁性箭袋

• DOI: 10.1007/jhep10(2021)014
• 发表时间: 2021
• 期刊: Journal of High Energy Physics
• 影响因子: 5.4
• 作者: Akhond M

Exploring the orthosymplectic zoo

• DOI: 10.1007/jhep05(2022)054
• 发表时间: 2022-03
• 期刊: Journal of High Energy Physics
• 影响因子: 5.4
• 作者: M. Akhond;F. Carta;Siddharth Dwivedi;Hirotaka Hayashi;Sung-Soo Kim;F. Yagi