'clumpy' cosmos expands non-uniformly ??

[Widdekind]

According to John Archibald Wheeler (Journey into Gravity & Space-time):

 

• matter tells space-time how to curve; and,
  
• curved space-time tells matter how to move
  

Now, beginning about 7 Gya, galaxies had 'clumped' together; and, evacuated inter-galactic deep-space; so that they stopped accreting new, fresh, primordial gas. Thus, galaxy growth has stalled; galaxies today have 10x less gas than 5 Gya; and, galaxies are forming stars 10-30x less rapidly, than 5 Gya (ABC AU 2011).

 

So, if, beginning about 7 Gya, inter-galactic 'voids' had been largely evacuated; and, if local matter-density determines local space-time curvature; then, c.7 Gya, would not most of our universal space-time fabric have started 'feeling under-dense', and started expanding much more rapidly, than surrounding regions, replete with galaxies & gas ?

 

Again, the 'FRW' equations, for an expanding cosmic space-time, assume uniformity, homogeneity, & isotropy. But, a 'clumpy' cosmos is none of those. Instead, as those assumptions begin to break down, our universal space-time fabric begins to resemble vast 'voids' of empty 'Einstein-de-Sitter' space-time, 'sutured' together, via gravitationally-bound filaments & nodes of the Cosmic Web, where-with-in space is non-expanding. Perhaps, then, as matter coagulates into 'clumps', our universal space-time fabric evolves into "a bunch of bowling balls scattered across an otherwise empty rubber sheet" -- which, in empty regions beyond the bowling balls, expands as an under-dense 'Einstein-de-Sitter' like space-time fabric ?

 

(

ABC AU 2011

)

[pantheory]

The present model asserts that space expands at the same rate during any given time frame within the observable universe. The idea is that within galaxies and galaxy clusters gravity counteracts expanding space so that expansion within galaxies and clusters is small or close to non-existent so that expansion cannot be observed there. In these spaces between galaxy clusters and within large voids gravity accordingly does not compensate for the alledged expansion of space so that the expansion of the universe that we believe we are observing by galactic redshifts, stems from these volumes and voids.