From supersymmetry, strings and branes to the LHC and cosmology.

拟议的研究是从最基本的层面理解自然的探索的一部分，从而形成单一、完整和一致的物理学理论。在小距离处，物质和力的行为受量子力学控制。自大约 40 年前标准模型的制定以来，人们就已经了解了亚原子电磁力、弱力和强力。这些力及其作用的粒子由量子场论描述，标准模型包含大量对称性对于数学一致性至关重要。标准模型在实验上取得了巨大的成功，最近在欧洲核子研究中心的大型强子对撞机 (LHC) 中发现了一个强有力的候选者，即希格斯玻色子，这是标准模型预测的最后一个尚未发现的粒子。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。不幸的是，广义相对论与量子力学不一致，因此不能简单地与标准模型结合以提供所有四种力的一致理论。标准模型也无法解释基础物理中质量尺度的层次结构、粒子类型的扩散以及宇宙中已知大量存在但尚未被发现的暗物质的性质。人们普遍认为，超对称性，即费米子（如电子）与玻色子（如光子）交换的对称性，将在制定四种力的统一理论中发挥重要作用。超对称性预测了尚未观测到的亚原子粒子的存在，对这些粒子的寻找是大型强子对撞机建造背后的重要动机。其中之一实际上可能是暗物质，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理论假设“基本”粒子实际上是延伸的复合物体，或者存在更多维度的空间。弦是沿一维延伸并且可以振动的微观物体，就像小提琴上的弦一样。尽管弦和膜的基本理论尚不清楚，但超引力理论完全描述了它们在低能量下的影响，并且通过研究这些理论，我们已经认识到称为膜的物体和称为对偶性的对称性是整个理论的重要组成部分。膜可以被认为是字符串到沿多个维度延伸的对象的概括。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个维度上产生一致的量子理论，同时也为标准模型之外的新颖物理学提供前景。拟议研究的一部分旨在找到并理解弦和膜的这一基本理论。尽管量子场论在理论和实验上取得了巨大的成功，导致了理论和实验之间最准确的确认，但精确计算的量却很少。近年来，某些弦理论与量子场论在四个维度上的对应关系被发现。这催生了前者的新技术，可以精确计算感兴趣的物理量。这是正在进行的研究的一部分，以及探索弦和膜对标准模型之外的物理学可能产生的影响，并了解大型强子对撞机、天体物理实验和宇宙​​学正在揭示哪些其他新物理学。

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 understood since the formulation of the Standard Model some 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 recent discovery at the Large Hadron Collider (LHC) at CERN of a strong candidate to be the Higgs Boson, 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. Unfortunately, General Relativity is not consistent with quantum mechanics and so cannot be simply 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 seen.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 yet unobserved subatomic particles, and the search for these was an important motivation behind the construction of the LHC. One of them could in fact be dark matter, and hence play an important role in forming structures 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 known, their effects at low energies are completely described by supergravity theories, and by studying these it has been realized that objects, called branes, and symmetries, called dualities, are important parts of the full theory. Branes can be thought of as generalizations 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 are very few quantities which have been computed exactly. In recent years, a correspondence between certain string theories and quantum field theories in four dimensions has been found. This has led to new techniques in the former that enable the exact computation of quantities of physical interest. This is part of the ongoing research, as well as exploring 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.