Kinematics and WorldStructure II.
Abstract
The equalions of motion of a test particle in an idealized universe satisfying the cos mological principle are obtained from the standpoint of the general kinematics devel oped in Part I of this paper, and are found to be determinate only to within an arbi trary function I' of two variables. Their integration is reduced, in principle, to the solu tion of a single firstorder ordinary differential equation. The acceleration function I' is determined and the integration completed upon imposing (a), the general relativistic theory of gravitation, thus showing the consistency of the general kinematics here de veloped with that theory, and also upon imposing (b), any suitable adaptation of the Newtonian theory of gravitation, ifiustrated in detail by a relativistic extension appli cable to the case in which the total mass of the fundamental particles (nebulae) is finite
 Publication:

The Astrophysical Journal
 Pub Date:
 April 1936
 DOI:
 10.1086/143716
 Bibcode:
 1936ApJ....83..187R