[X] My Assistant

[deglr6328]

Fred Cooperstock and Steven Tieu of Northeastern University and the University of Victoria respectively have a paper on arXiv which apparently shows that using general relativity with corrections for non-linear effects and other such things I do not understand results in a VERY good fit for the explanation of why galaxies rotate the way they do and thus removes any need for non-baryonic "dark matter" haloes around the galaxy! If it is a valid result and is verified it will be a really major discovery. Even CERN is now carrying a blurb about the paper.

[Guest_Myran_*]

'Dark energy' are a term sometime used for the cosmological constant, one idea proposed by Albert Einstein and which have had a renaissance in recent years. The idea of the cosmological constant had a comeback after astronomers measured the light from novas used as 'standard candles' to get distance and the velocity (redshift) for the galaxies they were part of.
The study (actually more than one) yielded the result that the galaxies in the universe appeared to increase their speed as the universe continues to expand, and one theory are that this was caused by 'dark energy' the term meaning that its unseen.

[blobrana]

The word on the street says that:
The theory fails when modelling the galactic rotation speeds of dwarf galaxies.
The theory fails to agree with observations near the galactic centre.
The theory derives the galactic density from the rotation curves- they should be doing it the other way around.
The small number of bright galaxies they chose have high inclination angles.
The theory fails to address why galaxy clusters are held together.

Singular disk of matter in the Cooperstock and Tieu galaxy model
Authors: Mikolaj Korzynski

Recently a new model of galactic gravitational field, based on ordinary General Relativity, has been proposed by Cooperstock and Tieu in which no exotic dark matter is needed to fit the observed rotation curve to a reasonable ordinary matter distribution. We argue that in this model the gravitational field is generated not only by the galaxy matter, but by a thin, singular disk as well.
The model should therefore be considered unphysical.

http://arxiv.org/PS_cache/astro-ph/pdf/0508/0508377.pdf (PDF)