Emmanuel,
I understand vacuum energy as that which permeates space and cosmic background radiation as the black body radiation emanating from the edge of the visible universe.
I guess it's obvious that I'm one of those who thinks Big Bang Theory, Inflationary Cosmology, or any other versions of the model are wrong and am looking for insights into how to otherwise explain the observed phenomena. Since it rests on the assumption that the only way light can be redshifted is by recession alone, this involves considering the nature of light and why I'm bothering you about it.
A question I would raise for you to think about, since you do seem to have been educated within the school that Big Bang theory is past the point of debate:
Originally it was assumed to be a normal expansion, but since it is observed that redshift is proportional to distance and there is no lateral motion to match redshift, it appeared that we are at the center of the universe, so the theory was changed to say that space itself expands, such that everything is pushed away from everything else, resulting in the isotropic appearance of every point being the center of its own view of the universe.
The problem I have with this is that the speed of light remains constant. According to the BBT, if two sources are x lightyears apart and the universe doubled in size, they would be 2x lightyears apart.
What, if the very fabric of space is being stretched, determines lightspeed? It provides a constant measure of distance. If space is being stretched, how does this measure remain constant?
Consider that with the normal Doppler effect, space is not being created by the train moving. It is simply putting space that was in front of it, behind it. Same for those galaxies. If they are redshifted according to the Doppler effect, they are not creating space, but moving away in it.
This then gets back to the problem of our position appearing as the center of the universe. If there is some sort of optical effect, rather than the actual recession of these galaxies, it would be quite logical that redshift is proportional to distance and there is no lateral motion to match.
Consider the effect of gravity bending light. This is an optical effect. That distant star, as it moves beyond the sun, does not actually shift back and forth. Merely the path of its light is bent. It makes far more sense that these distant galaxies are not actually moving away because we observe their light to be redshifted. So my quest is to consider what other factors could cause this light to become redshifted over such enormous distances.
Do we really understand all the properties of light to construct such a fantastical model of the universe and keep adding even more fantastical patches, from Inflation to Dark energy, in order to hold it together. It seems like a fairly classical case of herd behavior causing mass delusion. As has happened all to often in human history.