Non-perturbative and out-of-equilibrium field theories

物理学家对强相互作用的物理系统非常感兴趣。主要原因是量子色动力学（QCD），一种在核水平上控制亚原子粒子相互作用的理论，是强相互作用的。多年来，人们已经知道，量子光盘的这种特性导致了核物质的许多不寻常和有趣的特性。******然而，由几代物理学家开发的标准计算技术，主要是在量子电动力学（QED）的背景下，不适用于强耦合系统。由于这个原因，人们对这些系统的行为知之甚少。******在过去的10-20年里，已经开发了涉及粒子加速器的昂贵实验项目，例如在布鲁克海文国家实验室和欧洲核子研究中心，以经验研究强耦合系统。夸克胶子等离子体是在相对论性核碰撞中产生的，最近出现了许多令人兴奋的实验结果。由于所研究的系统在其演化之初的一段未知时间内处于不平衡状态，因此对这些结果的解释变得更加困难。******对于科学的进步来说，理论家与实验计划保持同步是很重要的。因此，在强耦合和非平衡系统中计算可观测值的理论技术的发展方面，最近有很多工作。这项工作既困难又令人兴奋。它涉及发明完全不同的数学方法来描述以前被认为超出我们数学描述能力的物理情况。我研究计划的一个目标是发展一种特殊的非微扰形式（称为n粒子不可约作用），并将其应用于强耦合量子场论。另一个主要目标是发展了解等离子体不稳定性的动力学作用的技术。

Physicists are very interested in physical systems that are strongly interacting. The main reason is that quantum chromodynamics (QCD), the theory that governs the interactions of subatomic particles on a nuclear level, is strongly interacting. It has been known for years that this property of QCD is responsible for many of the unusual and interesting properties of nuclear matter. ******However, the standard calculational techniques that have been developed by generations of physicists, largely in the context of quantum electro-dynamics (QED), are not applicable to strongly coupled systems. For this reason, the behavior of these systems is much less well understood. ******Over the past 10-20 years, expensive experimental programs involving particle accelerators have been developed, for example at Brookhaven National Laboratory and CERN, to study strongly coupled systems empirically. Quark gluon plasmas are produced in relativistic nuclear collisions, and many exciting experimental results have recently become available. The interpretation of these results is made even more difficult by the fact that the systems that are studied are out of equilibrium for an unknown period of time at the beginning of their evolution. ******It is important for the progress of science that theorists keep pace with experimental programs. Accordingly, there has been much recent work on the development of theoretical techniques to calculate observables in strongly coupled and non-equilibrated systems. This work is both difficult and exciting. It involves the invention of completely different mathematical methods to describe physical situations that were previously considered beyond our ability to describe mathematically. One goal of my research program is the development of a particular non-perturbative formalism (which is called the n-particle irreducible action), and its application to strongly coupled quantum field theories. Another major goal is the development of techniques to understand the dynamical role of plasma instabilities.