标题： 无穷远处的边界条件在物理理论中的应用 显示英文标题

标题： Boundary Conditions at Infinity for Physical Theories

摘要： Sommerfeld 边界条件被施加于双曲型微分方程以获得以向外传播波形式的解，此处的表述方式旨在明确适当零向量场的作用。 当应用于标量方程和麦克斯韦方程时，它们会导致表示辐射为零且完全无压物质的能量-动量张量的渐近形式。 显示英文摘要

摘要： The Sommerfeld boundary conditions, imposed on hyperbolic differential equations to obtain solutions in the form of outgoing waves, are formulated here so as to make explicit the role of an appropriate null vector field. When applied to the scalar and Maxwell equations, they lead to the asymptotic form of the energy-momentum tensor representing radiation as a null, perfect dust.