Necessity of Dark Energy Questioned

ttnuagmada points us to an article about scientist David Wiltshire's suggestion that theorized dark energy is not needed to describe the expansion of the universe. His work challenges assumptions made about the distribution of matter in the universe. Early solutions to general relativity were based on a "smooth distribution" of matter. Wiltshire's approach focuses on a "lumpy" dispersal, which more accurately fits data from modern studies. We have discussed other theories about dark energy in the past. Quoting: "Through observational projects like the Sloan Digital Sky Survey and the 2 Degree Field survey, we now have a much better picture of the large-scale structure of the universe and we know that galaxies are not uniformly distributed. 'Rather, they are in clusters sprinkled thinly in filaments and "bubble walls" surrounding huge voids hundreds of millions of light-years across,' Wiltshire says.

Comments

Re:Mini-Inflation events in Voids

[LionKimbro]

I don't think so; My understanding is that it's the force of gravity.

Here is the picture I have heard:

The universe basically, from any point, stretches out in all directions. Gravity pulls a given lump in all directions at a given time. But local things are more powerful by the law of gravity, than far things. So things start lumping with their neighbors.

Some lumpings occur earlier than other lumpings, which cause then to exert a stronger pull. These become the super-clusters (joining points between filament; such as the Virgo Cluster.)

So masses are basically pulled towards the closest super-cluster. But, ah-hah, some are pulled strongly by *two* super-clusters. These become the filament ("bubble walls.")

If you download Mitaka, you can see a lot of these things first hand, with data directly from the Sloan Digital Sky Survey.