局域规范变换中协变导数D_μ的作用新探

A New Study on the Role of Covariant Derivative D_μ in Local Gauge Transformation

局域规范变换通过协变导数引进规范场 体现电磁作用的理解是不准确的。其实,对自由带电粒子作局域规范变换时就引进了电磁场作用。通过协变导数引进规范场 是消除局域规范变换引进的电磁场作用。这是恢复带电粒子自由运动状态和洛仑兹协变,保证狄拉克方程形式不变性的物理数学操作。

It is not accurate to say that electromagnetic action is represented by introducing gauge field through covariant derivative. In fact, the local gauge transformation of charged free particles in-troduces electromagnetic fields. The introduction of gauge field by covariant derivative eli-minates the effect of electromagnetic field introduced by local gauge transformation. This is a physical and mathematical operation to restore the free motion state of charged particles and Lo-rentz covariant to ensure the form invariance of Dirac equation.