论文标题
电力自力有力对移动系统中电磁势头的贡献
Contribution of electric self-forces to electromagnetic momentum in a moving system
论文作者
论文摘要
在移动电磁系统中，根据矢量电势计算出的电磁动量与系统的场能成正比。这样获得的动量实际上与从系统的静电帧电磁能的洛伦兹转化得出的相同，假设电磁能摩托明是4载体。然而，电磁场形成的能量弹药密度是电磁应力 - 能量张量的成分，它们从静止框架到另一个帧的转化涉及麦克斯韦应力张量中的压力项的额外贡献，这些贡献在从矢量电位中计算出的动量中未能表示的麦克斯韦压力张量。这些额外贡献的起源是由电磁场中的压力引起的，可以从物理的角度来追溯到有助于移动系统的电磁动量的电力自我强度，这可能并不总是很明显。 Such subtle contributions to the electromagnetic momentum from stress in electromagnetic fields that could be significant even for non-relativistic motion of the system, lead in fact, to resolution of some curious riddles in the electromagnetic momentum of such systems, e.g., the apparent paradox of a {\em nil} electromagnetic momentum in a charged parallel-plate capacitor, moving perpendicular to the plate取向，尽管移动系统载有有限的电磁能。电磁场中的压力的这种贡献也为在移动带电的球体的电磁动量中遇到的著名，百年历史的4/3的著名，神秘因素提供了自然解决方案。
In moving electromagnetic systems, electromagnetic momentum calculated from the vector potential is shown to be proportional to the field energy of the system. The momentum thus obtained is shown actually to be the same as derived from a Lorentz transformation of the rest-frame electromagnetic energy of the system, assuming electromagnetic energy-momentum to be a 4-vector. The energy-momentum densities of electromagnetic fields form, however, components of the electromagnetic stress-energy tensor, and their transformations from rest frame to another frame involve additional contributions from stress terms in the Maxwell stress tensor which do not get represented in the momentum calculated from the vector potential. The genesis of these additional contributions, arising from stress in the electromagnetic fields, can be traced, from a physical perspective, to electric self-forces contributing to the electromagnetic momentum of moving systems that might not always be very obvious. Such subtle contributions to the electromagnetic momentum from stress in electromagnetic fields that could be significant even for non-relativistic motion of the system, lead in fact, to resolution of some curious riddles in the electromagnetic momentum of such systems, e.g., the apparent paradox of a {\em nil} electromagnetic momentum in a charged parallel-plate capacitor, moving perpendicular to the plate orientations, in spite of the moving system carrying finite electromagnetic energy within it. Such contributions from stress in electromagnetic fields also provide a natural solution to the famous, century-old, enigmatic factor of 4/3, encountered in the electromagnetic momentum of a moving charged sphere.
