论文标题
扭转引起的重力$θ$术语和重力电信
Torsion-induced gravitational $θ$ term and gravitoelectromagnetism
论文作者
论文摘要
我们是由一般相对论的弱场扩张与麦克斯韦的电动力学定律之间的类比进行的，我们探索了均违反gravitoelectromagnetism中$θ$术语的物理后果。这与作为Riemann Tensor的平方形成的常见重力$θ$项不同。取而代之的是，它是拉格朗日语中引力和引力磁场的产物，类似于麦克斯韦$θ$项。我们表明，这个部门可能是由非线性重力中的二次扭转项引起的。与拓扑绝缘体的物理学类似，扭转引起的$θ$参数可以导致$θ$变化的区域的界面过度质量密度，因此它对牛顿的重力定律产生了校正。我们还讨论了引力对起的Witten效应的类似物。
Motivated by the analogy between a weak field expansion of general relativity and Maxwell's laws of electrodynamics, we explore physical consequences of a parity violating $θ$ term in gravitoelectromagnetism. This is distinct from the common gravitational $θ$ term formed as a square of the Riemann tensor. Instead it appears as a product of the gravitoelectric and gravitomagnetic fields in the Lagrangian, similar to the Maxwellian $θ$ term. We show that this sector can arise from a quadratic torsion term in nonlinear gravity. In analogy to the physics of topological insulators, the torsion-induced $θ$ parameter can lead to excess mass density at the interface of regions where $θ$ varies and consequently it generates a correction to Newton's law of gravity. We discuss also an analogue of the Witten effect for gravitational dyons.
