Abstract—The flux density vector of the electromagnetic energy in the Poynting form and the problem of the electron electromagnetic momentum, associated with this definition, are considered. The alternative flux density definition, i.e., the Umov vector whose value is identical to the Poynting vector only for empty space, is also analyzed. For qualitative comparison of differential and integral values of these two vectors in the case of non-empty space, the model of the extended electron whose charge density is inversely proportional to the quartic distance from the symmetry center is studied. It is shown that the Umov vector in this case appears more universal, since the corresponding energy conservation law does not contain a term responsible for the electromagnetic energy conversion to other energy types.

中文翻译：

---

扩展电子均匀运动过程中Umov电磁能的通量密度

摘要—考虑了与此定义相关的Poynting形式的电磁能的通量密度向量和电子电磁动量问题。还分析了替代通量密度定义，即，Umov向量的值仅与空白空间的Poynting向量相同。为了在非空空间情况下定性比较这两个向量的微分和积分值，研究了电荷密度与距对称中心四次距离成反比的扩展电子模型。可以看出，在这种情况下，Umov向量显得更为通用，因为相应的能量守恒定律不包含负责将电磁能转换为其他能量类型的术语。