Constraints in Electrodynamics and Quantization of the Electromagnetic Field Without Charges

摘要

The degrees of freedom of the electromagnetic field is discussed. It is pointed out that a single complex function, which satisfies a two-dimensional wave equation, can be defined to describe the dynamics of the Maxwell field. The canonical quantization procedure is then applied to quantize this wave equation for the case without charges. As a result, the electromagnetic field is effectively quantized, with the familiar problem of constraints becoming redundant. (Author)