Welcome to Hubert L. Bray's

Dark Matter Webpage.


Paper:
``On Dark Matter, Spiral Galaxies, and the Axioms of General Relativity,'' H. Bray, April 22, 2010.

Abstract:
Beginning with a geometric motivation for dark matter going back to the axioms of general relativity, we show how scalar field dark matter, which naturally forms dark matter density waves due to its wave nature, may cause the observed barred spiral pattern density waves in many disk galaxies and triaxial shapes with plausible brightness profiles in many elliptical galaxies. If correct, this would provide a unified explanation for spirals and bars in spiral galaxies and for the brightness profiles of elliptical galaxies. We compare the results of preliminary computer simulations with photos of actual galaxies.


Spiral Galaxy Simulation using Matlab:

spiralgalaxy.m


Elliptical Galaxy Simulation using Matlab:

ellipticalgalaxy.m


Right click on the above links to download the files.  The two .m files can be run using Matlab.  As these .m files create many image files, we suggest creating a new directory for each run and placing a copy of the .m file in that directory.  Then change to that directory inside Matlab and execute the command line.  If you open the .m files in the Matlab editor, example command lines are listed.  There are also example command lines in the paper listed above as well.

Have fun!

Hubert L. Bray
Mathematics Department
Duke University, Box 90320
Durham, NC  27708  USA
bray@math.duke.edu