轻触 发表于 2025-3-30 10:15:28
Riemannian Manifolds,n laws to infinitesimal triangles. For this purpose, the laws of similar triangles must be adopted ab initio as postulates, and the ‘postulate of parallels’ must be excluded, a procedure that is reasonable as far as physics is concerned both because the laws of similar triangles correspond immediate漂浮 发表于 2025-3-30 14:58:09
,Weak Field Approximation. Newton’s Theory,le of equivalence, which says that every valid Lorentz invariant theory can be immediately generalized to a valid general relativistic theory by first presenting the formalism of the theory in standard Minkowski (canonical) coordinates and then converting all ordinary spacetime derivatives to covari注视 发表于 2025-3-30 20:15:17
http://reply.papertrans.cn/20/1914/191367/191367_53.png烦躁的女人 发表于 2025-3-30 21:43:26
Conservation Laws,pretation can obviously be extended also to particle ensembles and gases. When we speak of fluxes we usually think of quantities that are conserved. In special relativity, energy and momentum are conserved. In general relativity, they are no longer generally conserved, at least if we do not include周兴旺 发表于 2025-3-31 04:23:15
Phenomenological Description of a Conservative Continuous Medium, in electromagnetic theory. However, because matter in . its forms is coupled to the gravitational field, this source can be much more complicated than electric charge. Many times we may wish to find the gravitational field produced by a certain material system without knowing or being able to write鉴赏家 发表于 2025-3-31 08:33:21
Solubility of the Einstein and Matter Equations,em. There must be precisely enough equations to determine uniquely the full physical evolution of the system, once initial conditions have been specified. We now examine this problem for the Einstein and matter equations.