Fundamental Physics from the Planck Scale to the LHC

这项拟议中的研究是在最基本的层面上理解自然的探索的一部分，从而形成一个单一、完整和一致的物理学理论。在很小的距离上，物质和力的行为受量子力学的支配。自从40多年前标准模型建立以来，亚原子电磁力、弱力和强力已经得到了很好的理解。这些力和它们所作用的粒子由量子场论描述，标准模型包含大量的对称性对于数学的一致性至关重要。2012年，在大型强子对撞机（LHC）上发现了希格斯玻色子（Higgs Boson），这是标准模型预测的最后一个粒子，但还没有被发现。我们目前对引力的描述是爱因斯坦非常成功的广义相对论，它描述了行星、恒星和星系以及整个宇宙的运动。然而，广义相对论与量子力学并不一致，因此不能与标准模型相结合，以提供所有四种力的一致理论。标准模型也未能解释基础物理学中质量尺度的层次结构、粒子类型的扩散以及宇宙中暗物质的性质。已知暗物质大量存在，但尚未被探测到。人们普遍认为，超对称性，即交换费米子的对称性（如电子）与玻色子（如光子）的相互作用，将在建立四种力的统一理论中发挥重要作用。超对称性预言了还存在着一些尚未被观测到的亚原子粒子，而对这些粒子的探索是建造大型强子对撞机的重要动机。事实上，其中之一可能是暗物质，因此在宇宙结构的形成中发挥着重要作用。标准模型之外的其他物理学理论假设“基本”粒子实际上是扩展的复合物体，或者存在更多的空间维度。弦是一种微观物体，它沿着一维延伸，可以振动，就像小提琴上的弦一样。虽然弦和膜的基本理论还没有完全被理解，但它们在低能时的效应完全由超引力理论描述，通过研究这些理论，人们已经认识到，称为膜的物体和称为对偶的对称性是完整理论的重要组成部分。膜可以被认为是弦到沿着不止一维延伸的对象的概括。值得注意的是，人们发现弦和膜可以在包含引力和标准模型的四维空间中产生一致的量子理论，同时也为标准模型之外的新物理学提供了前景。这项研究的一部分目的是发现和理解弦和膜的基本理论。虽然量子场论在理论和实验上都取得了惊人的成功，导致理论和实验之间得到了最精确的证实，但在超对称出现之前，几乎没有任何量被精确计算过。我们研究的另一部分是进一步发展新技术，这些技术已经导致某些超对称量子场论中相当多的重要量的精确计算。这使人们希望能够完全计算这些理论中的所有量。我们还将探索弦和膜对标准模型之外的物理学的可能影响，并了解LHC，天体物理实验和宇宙学揭示的其他新物理学。

The proposed research is part of a quest to understand Nature at its most fundamental level, leading to a single, complete and consistent theory of physics. At small distances the behaviour of matter and forces is governed by quantum mechanics. The subatomic electromagnetic, weak and strong forces have been well understood since the formulation of the Standard Model over 40 years ago. These forces and the particles they act upon are described by quantum field theory and it is crucial for mathematical consistency that the Standard Model incorporates a large amount of symmetry. The Standard Model has enjoyed spectacular experimental success, culminating in the 2012 discovery of the Higgs Boson at the Large Hadron Collider (LHC), the last particle predicted by the Standard Model that remained to be found. Our current description of gravity is Einstein's very successful theory of General Relativity, which describes the motion of planets, stars and galaxies as well as the Universe as a whole. However General Relativity is not consistent with quantum mechanics and so cannot be combined with the Standard Model to provide a consistent theory of all the four forces. The Standard Model also fails to explain the hierarchy of mass scales in fundamental physics, the proliferation of particle types and the nature of the dark matter in the Universe, which is known to be present in large quantities but has not yet been detected.It is widely believed that supersymmetry, which is a symmetry that exchanges fermions (such as the electron) with bosons (such as the photon), will play an important role in formulating a unified theory of the four forces. Supersymmetry predicts the existence of additional subatomic particles which have yet to be observed, and the search for these was an important motivation behind the construction of the LHC. Indeed one of them could be dark matter, and hence play an important role structure formation in the universe. Other theories of physics beyond the Standard Model postulate that `elementary' particles are in fact extended, composite objects, or that there are more dimensions of space. Strings are microscopic objects that are extended along one dimension and can vibrate, rather like strings on a violin. Although the underlying theory of strings and branes is not fully understood, their effects at low energies are completely described by supergravity theories and by studying these it has been realised that objects, called branes, and symmetries, called dualities, are important parts of the complete theory. Branes can be thought of as generalisations of strings to objects that are extended along more than one dimension. Remarkably, one finds that strings and branes can lead to consistent quantum theories in four dimensions that contain gravity as well as the Standard Model, while also offering prospects for novel physics beyond the Standard Model. Part of the proposed research aims to find and understand this underlying theory of string and branes. Although quantum field theories have had spectacular theoretical and experimental success leading to the most accurately known confirmation between theory and experiment, there were, until the advent of supersymmetry, almost no quantities which have been computed exactly. Another part of our research is to further develop new techniques that have lead to the exact calculation of quite a number of important quantities in certain supersymmetric quantum field theories. This has lead to the hope that one can completely compute all quantities in such theories. We will also explore the possible consequences of strings and branes for physics beyond the Standard Model, and understanding what other new physics is being revealed by the LHC,astrophysical experiments and cosmology.