发表机构
School of Intelligent Engineering, Shaoguan University; Center for Gravitation and Cosmology, College of Physical Science and Technology, Yangzhou University（韶关学院智能工程学院; 扬州大学物理科学与技术学院引力与宇宙学中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文构造两种几何下的宇称破坏卡鲁扎-克莱因模型，发现标架引力几何中无鬼场，且预测电磁波与引力波螺旋度色散位移满足6倍关系，可通过联合观测检验统一理论。
AI 中文摘要
引力与电磁领域的宇称破坏已被广泛研究，但传统上二者被视为独立现象。然而这种分离可能是一种四维偏见：在高维时空中，引力与电磁学可能共享共同的几何起源，其宇称破坏也可能同源。本文通过构造黎曼几何和标架引力（teleparallel）几何中的宇称破坏卡鲁扎-克莱因（Kaluza-Klein）模型来探索这一想法。在黎曼几何中，最简单的五维宇称破坏项会分解为多个复杂的四维项，包括存在鬼场不稳定性的熟知引力陈-西蒙斯（Chern-Simons）项；而在标架引力几何中，结果显著简单，最简单的五维宇称破坏项仅分解为两个无鬼场的项——熟知的尼赫-杨（Nieh-Yan）项和标准电磁陈-西蒙斯项。该模型预测电磁波的螺旋度相关色散位移恰好是引力波的6倍，即Δω²_EM=6Δω²_GW，这是与背景无关的关系，为通过联合宇宙微波背景与引力波双折射观测检验统一理论提供了可证伪的测试依据。
英文摘要
Parity violation in the gravitational and electromagnetic sectors has been extensively investigated, yet the two are conventionally treated as independent phenomena. This separation, however, may be a four-dimensional prejudice. In higher-dimensional spacetime, gravity and electromagnetism may share a common geometric origin---and so, perhaps, does their parity violation. In this paper, we pursue this idea by constructing parity-violating Kaluza-Klein models in both Riemannian and teleparallel geometries. In Riemannian geometry, the simplest five-dimensional parity-violating term reduces to several complicated four-dimensional terms, including the familiar gravitational Chern-Simons term, which suffers from a ghost instability. In teleparallel geometry, however, the result is strikingly simple. The simplest five-dimensional parity-violating term reduces to only two ghost-free terms---the familiar Nieh-Yan term and the standard electromagnetic Chern-Simons term. Remarkably, the model predicts that the helicity-dependent dispersion shift for electromagnetic waves is exactly six times that for gravitational waves, $Δω^{2}_{ EM}=6\,Δω^{2}_{GW}$, a background-independent relation. This relation offers a falsifiable test of unification through joint cosmic microwave background and gravitational wave birefringence observations.
Comments22 pages, 0 figures
