Expansion of Universe Accelleration an Illusion?

The 1998 discovery based on the rate of recession of distant quasars and/or supernova that the Universe may have begun accellerating its expansion about 5 billion years ago is generally accepted by physicists-at least until this recent theory by Christos Tsagas.

http://www.space.com/13094-accelerating-universe-dark-energy-illusion.html

The space.com article is quite informative. After Allan Guth developed the inflation theory of universal expansion the idea that space had not only originated in a Lamaitre like big bang but also had an expansion allowed an updated sketching in of the overall shape and rate of change of space-time.

The universe at 10 to the minus 43 second of its history was hot and dense in the theory, then at 10 to the minus 35th second it hyper-inflated faster than the speed of light. Neither light or gravity actually existed then, and so the universe expanded in a small fraction of a second to the size of a grapefruit (probably a Florida rather than a California grapefruit) and slowed to resume its normal sub-lght speed expansion for billions of years.

What was thought to drive the first inflation was a phase change to a lower more stable energy level of vacuum energy. That consolidation through off radiation and maybe space increased simultaneously. That vacuum energy is what remains in the universe today possibly as the cosmological constant or Lambda that was thought to be expanding it again towards dissipation. Now it is conjectured the apparent expansion of the universe could be just an illusion made because different regions of space may have different relative velocities or shapes in comparison to other regions of the universe.

If the cosmological constant is not real, and if the universe is not increasing its rate of expansion but is instead sort of just hanging on the critical edge between expanind and collapsing toward a big crunch, then some of these other theories about inflation may lose some coinciding support.

I am not sure that it matters too much right now expecpt perhaps to professisonal physicists since several basic ideas about space, mass and energy are also rather unknown. Most of the physical theories describing mass and energy really haven't a good definition of what space is for itself. Quantum mechanics seems to be more a description of the phenomenal appearance of the observed behavior of sub-atomic particles rather than a philosophy of what the nature of the quantum reality is in-itself.

Hopefully theorists will wrap up these interesting questions and produce solid answers before time runs out in the Universe or in the chaotic inflationary cascade of universes that may or may not have arisen from the inexplicable donation of a vacuum energy with a preferred direction.