Green Function 先举一个静电场的例子 无界空间中有一定电荷分布,电荷密度p(r) 在坐标为r′=(x3,y/,z2)的体元dr内的电量即 为p(r)dr',它在空间r=(x,y,x)点的电势是 1p( 4πor 根据电势叠加原理,把空间中的全部电荷产 生的电势叠加起来,就得到在点的总电势为Concept of Green Functions Green Functions in Time-Independent Problems Green Ftns of 3D Holmholtz eq. Superposition Principles in Infinite Space Green Functions in Finite Space: Definition kއ·>|~f Ã.m¥k½>Ö©Ù§>ÖÝρ(r) 3‹Ir 0 = (x 0 , y0 , z0 )N dr 0S>þ= ρ(r 0 )dr 0 § §3mr = (x, y, z):>³´ 1 4πε0 ρ(r 0 ) |r − r 0 | dr 0 Šâ>³U\n§rm¥Ü>Ö )>³U\å5§Ò3r:o>³ φ(r) = 1 4πε0 ZZZ ρ(r 0 ) |r − r 0 | dr 0 C. S. Wu 1›Êù Green¼ê()