Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On Wave Dark Matter, Shells in Elliptical Galaxies, and the Axioms of
  General Relativity   This paper is a sequel to the author's paper entitled "On Dark Matter, Spiral
Galaxies, and the Axioms of General Relativity" [arXiv:1004.4016] which
explored a geometrically natural axiomatic definition for dark matter modeled
by a scalar field satisfying the Einstein-Klein-Gordon wave equations which,
after much calculation, was shown to be consistent with the observed spiral and
barred spiral patterns in disk galaxies. 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.

15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol