论文标题
关于具有化学势的相对论标量模型的评论
Remarks on relativistic scalar models with chemical potential
论文作者
论文摘要
我们讨论了具有非零化学势的经典相对论标量理论的选定方面。首先，我们在拉格朗日形式主义中对非零密度的古典田地理论进行了综述。所涵盖的方面包括使用化学势或时间依赖的现场配置的有限密度状态描述的问题，其最小化的哈密顿量的选择产生了有限密度的平衡状态以及破坏洛伦兹不变性的问题。其次，我们证明了如何通过整合繁重（HIGGS）字段来明确地解决NAMBU-GOLDSTONE（NG）模式的低能有效田间理论（NG）模式。这使得可以分析NG模式及其相互作用的频谱，而不必处理NG和Higgs字段的混合，这在自发对称性破坏的线性 - 微型模型中无处不在。
We discuss selected aspects of classical relativistic scalar field theories with nonzero chemical potential. First, we offer a review of classical field theory at nonzero density within the Lagrangian formalism. The aspects covered include the question of equivalence of descriptions of finite-density states using a chemical potential or time-dependent field configurations, the choice of Hamiltonian whose minimization yields the finite-density equilibrium state, and the issue of breaking of Lorentz invariance. Second, we demonstrate how the low-energy effective field theory for Nambu-Goldstone (NG) modes arising from the spontaneous breakdown of global internal symmetries can be worked out explicitly by integrating out the heavy (Higgs) fields. This makes it possible to analyze the spectrum of NG modes and their interactions without having to deal with mixing of NG and Higgs fields, ubiquitous in the linear-sigma-model description of spontaneous symmetry breaking.
