标题： 光子螺旋度和弯曲时空中的量子反常 显示英文标题

标题： Photon helicity and quantum anomalies in curved spacetimes

摘要： 我们比较文献中几种光子螺旋度（磁性、电性、电磁性）的定义。 在弯曲时空中，量子反常可能会破坏螺旋度守恒，根据这些定义，会对光子产生不同的影响：要么旋转线性偏振，要么产生圆偏振。 我们从明显不变的拉格朗日量出发，推导与对偶变换相关的诺特定律电流。 显示英文摘要

摘要： We compare several definitions of photon helicity (magnetic, electric, electromagnetic) present in literature. In curved spacetime quantum anomalies can spoil helicity conservation inducing, according to these definitions, different effects on photons: either rotation of linear polarization or production of circular polarization. We derive the Noether current associated with duality transformations starting from manifestly invariant Lagrangians.