Cosmic field strength
Cosmic field strength inside the sphere
Cosmic field strength outside the sphere
When cosmic radius become critical value, cosmic field strength is zero everywhere inside the sphere, that is line segment OA in Fig. 1; Outside the sphere, the magnitude of repulsive field strength is line AB
When cosmic radius is expanded to a1 , the gravitational field strength inside the sphere is line segment OA1 and outside the sphere is curve A1C ; the repulsive field strength is line OB inside or outside the sphere.
We get the following conclusion from the feature of cosmic field strength:
1) the repulsion expansion began with outmost layer and extends into inner. Hence Hubble’s constant of outmost layer is a little larger than inner. Certainly, if the travel velocity of light have to be considered, their difference is still less
2) Following the expansion increase, cosmic field strength inside and outside the sphere tend to the same change (for example a > 3 ). This is the cause that cosmic boundary is not quite distinct now of.