Welcome to Hubert L. Bray's

Wave Dark Matter Web Page

Paper #1:
``On Dark Matter, Spiral Galaxies, and the Axioms of General Relativity,'' H. Bray, April 22, 2010.

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.

Click here for the video of a lecture with a description of the above paper plus more recent ideas.  This talk, entitled "On Dark Matter, Spiral Galaxies, and the Axioms of General Relativity" was given at the 41st Barrett Memorial Lectures in Mathematical Relativity at the University of Tennessee, Knoxville on May 12, 2011.  A similar talk was also given at the 26th Annual Geometry Festival at the University of Pennsylvania on April 15, 2011.  The pdf slide show is here.

Click here for the video of a lecture entitled "Dark Matter in Galaxies" that Andriy Badin and I gave at Duke University as part of Dark Matter Awareness Week on December 6, 2010.  The last 25 minutes gives an overview of the above paper.

Spiral Galaxy Simulation using Matlab:

Elliptical Galaxy Simulation using Matlab:


Paper #2:
``On Wave Dark Matter, Shells in Elliptical Galaxies, and the Axioms of General Relativity,'' H. Bray, December 22, 2012.

This paper is a sequel to the paper listed above.  We give an update on where things stand on this ``wave dark matter'' model of dark matter (aka scalar field dark matter and boson stars), an interesting alternative to the WIMP model of dark matter, and discuss how it has the potential to help explain the long-observed interleaved shell patterns, also known as ripples, in the images of elliptical galaxies.

Shells in Elliptical Galaxies Visualization using Matlab:

Paper #3
``Modeling Wave Dark Matter in Dwarf Spheroidal Galaxies," H. Bray and A. Parry, January 2013.

We compare the mass profiles of spherically symmetric static states of wave dark matter to the Burkert mass profiles that have been shown by Salucci et. al. to predict well the velocity dispersion profiles of the eight classical dwarf spheroidal galaxies.  We show that a reasonable working value for the fundamental constant Upsilon in the wave dark matter model is 50 years^(-1).  We also show that under precise assumptions the value of Upsilon can be bounded above by 1000 years^(-1). 

Matlab code used in this paper, zipped with readme.txt file included:
Modeling WDM in Dsph programs.zip

Paper #3 is based in part on:

Paper #4
``Spherically Symmetric Static States of Wave Dark Matter,'' by A. Parry, December 2012.

Right click on the above links to download the files.  The .m files can be run using Matlab.  As some of 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 usually listed.  There are also example command lines in the papers listed above as well.

Have fun!

Hubert L. Bray
Mathematics and Physics Departments
Duke University, Box 90320
Durham, NC  27708  USA