Conformal Gravity Challenge to Dark Energy & Dark Matter Theories

On Oct 28, 2011, at 12:35 PM, art wagner wrote:

Looks pretty good -   http://xxx.lanl.gov/find/hep-th/1/au:+Mannheim_P/0/1/0/all/0/1


OK, it does look important having read more of the paper. Definitely needs to be considered. Be interested to see what the Top Guns in GR think about it - if they read it.

"With the conformal theory being a consistent and renormalizable quantum theory at the microscopic
level, then just as with electrodynamics, one is assured that its macroscopic classical
predictions are reliable and not destroyed by quantum corrections. Consequently, application of the
theory to macroscopic astrophysical phenomena allows one to test the theory. Early work in this
direction was provided in [8] where the theory was used to successfully fit the rotation curves of a
set of 11 spiral galaxies, with the mass to light ratios (M/L) of the luminous optical disks of each of
the galaxies being the only free parameters, and with no dark matter being required. More recently
a systematic, broad-based study [9, 10, 11] of rotation curves extended the fitting to a total of 133
galaxies (a varied sample consisting of high surface brightness, low surface brightness, and dwarf
galaxies), and again acceptable fitting was obtained with the mass to light ratios of the galactic
optical disks being the only free parameters, and again with no dark matter being required. The
success of conformal gravity in fitting no less than 133 galactic rotation curves with just one free
parameter per galaxy is very encouraging for the theory. And with its not needing to invoke dark
matter, the very success of the fitting calls into question the validity of dark matter theory, where
in addition to the optical disk mass to light ratios, one typically needs two free parameters for each
galactic dark matter halo, and a thus additional 266 free parameters for the 133 galaxy sample.
For cosmological applications, conformal gravity has been found capable of providing a natural
explanation for the accelerating Universe supernovae data [12, 1]. Specifically, in the conformal
theory the background Robertson-Walker (RW) cosmology is found to naturally be an accelerating
one at all redshifts, so that unlike the situation that occurs in the standard cosmology, in the
conformal case there is no need to fine-tune the theory so as to force the Universe to transition from
deceleration to acceleration at a late redshift of order one. The conformal theory thus naturally
addresses the dark energy problem that challenges the standard cosmological theory."