标题： 从已知解生成新的完美流体解 II 显示英文标题

标题： Generating New Perfect-fluid Solutions From Known Ones II

摘要： 从已知的完美流体解生成新的完美流体解的变换的性质被进一步研究。 假设流体的四速度与静态Killing场平行，并且静态Killing场的模和扭力势之间存在函数关系。 这种情况是对我们之前论文中研究的情况的补充。 该变换只能在等温方程状态 rho+3p=0 的情况下，或者 alternatively 在静态时空的情况下，用于从已知的解生成可能的新完美流体解。 对于静态时空，我们的方法恢复了Buchdahl变换。 此外，还证明了Herlt从静态解构造静止完美流体解的技术实际上是本文所考虑方法的一个特例。 显示英文摘要

摘要： The properties of a transformation previously considered for generating new perfect-fluid solutions from known ones are further investigated. It is assumed that the four-velocity of the fluid is parallel to the stationary Killing field, and also that the norm and the twist potential of the stationary Killing field are functionally related. This case is complementary to the case studied in our previous paper. The transformation can be applied to generate possibly new perfect-fluid solutions from known ones only for the case of barotropic equation of state rho+3p=0 or, alternatively, for the case of a static spacetime. For static spacetimes our method recovers the Buchdahl transformation. It is demonstrated, moreover, that Herlt's technique for constructing stationary perfect-fluid solutions from static ones is, actually, a special case of the method considered in the present paper.