Nonperturbative physics in sigma models

西格玛模型中的非微扰物理

• 批准号: 332396356
• 负责人: Dr. Falk Bruckmann
• 金额: --
• 依托单位: Institut für Theoretische Physik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/332396356?language=en
• 关键词: Nonperturbative; physics; sigma; models

Two-dimensional sigma models are prominent strongly coupled systems sharing asymptotic freedom, a dynamically generated mass-gap and other important properties with Quantum chromodynamics. Recently, two very interesting nonperturbative effects have been studied in these systems: the cancellation of perturbative renormalon singularities by fractional instanton contributions and the generation of a nonzero charge density by a chemical potential through a formulation in terms of dual variables. Both topics shall be advanced in this project, mainly using lattice techniques. Discretisations on space-time lattices are one of the very few ab initio approaches to nonperturbative physics. The project aims at checking the renormalon conjecture in these models numerically as well as further developing dual variables for structural questions and specific simulations at nonzero density and beyond.

二维sigma模型是突出的强耦合系统，具有渐近自由、动态生成的质量间隙和量子色动力学的其他重要性质。最近，在这些系统中研究了两个非常有趣的非摄动效应：通过分数阶瞬时子贡献抵消摄动重整子奇点和通过对偶变量公式由化学势产生非零电荷密度。这两个主题都将在这个项目中推进，主要使用点阵技术。时空晶格上的离散是研究非微扰物理的极少数从头计算方法之一。该项目旨在对这些模型中的重整猜想进行数值检验，并进一步为结构问题和非零密度及以上的特定模拟开发对偶变量。