标题： 关于引力中的简化树图 显示英文标题

标题： On the simplified tree graphs in gravity

摘要： 首先，我给出之前假设的错误原因，即在一个引力不参与维持系统稳定的系统中，压力的体积积分可能不为零。 其次，在第一个非线性近似中，我以两种不同的方式在协调和各向同性坐标下得到了内部和外部施瓦茨希尔德解。 一种方法是从标准解出发并进行适当坐标变换。 另一种方法是使用扰动理论，结合施温格和温伯格源方法的元素。 这种方法适用于一般情况，并且在已知的简单例子如施瓦茨希尔德解上研究其所有特殊性质是有用的。 结果表明，这种方法比Duff之前提出的S度量方法更简单，并且更有信息量，因为它显示了来自空间哪个区域的贡献。 显示英文摘要

摘要： Firstly, I give the reason why is wrong my previously made assumption that the volume integral over the pressure may not be zero in a system where the gravitation plays no role in holding the system together. Secondly, in the first nonlinear approximation I obtain the inner and outer Schwarzschild solutions in harmonic and isotropic coordinates in two different ways. One way is to start from standard solution and make the appropriate coordinate transformation. The other way is to use the perturbation theory with elements of Schwinger and Weinberg source approach. This latter method is applicable in general case and it is useful to study all its peculiarities on known simple example such as Schwarzschild solution. It turns out that this method is simpler then S-metrics approach (previously made by Duff) and more informative as it it shows which contribution comes from what region of space.