通过双曲型方程的Hadamard基本解理论,将Huygens算子识别问题转化为双曲型方程的系数满足的关系,找出了更多的Huygens算子,从而推广了Stellmacher的结果,并解析了Veselov和Berest给出的一类Huygens算子与Stellmacher算子的关系.
In this paper, using Hadamard fundamental solutions of hyperbolic equations, Huygens' operator problem is converted into a relation that the hyperbolic equation coefficients satisfy, then more Huygens operators are found, and the Stellmacher' result is generalized. Furthermore, we prove that the Huygens operators by Veselov and Berest sre similiar to the Stellmacher' operators.