Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Vector field and rotational curves in dark galactic halos   We study equations of a non-gauge vector field in a spherically symmetric
static metric. The constant vector field with a scale arrangement of
components: the time component about the Planck mass m_{Pl} and the radial
component about M suppressed with respect to the Planck mass, serves as a
source of metric reproducing flat rotation curves in dark halos of spiral
galaxies, so that the velocity of rotation v_0 is determined by the hierarchy
of scales: \sqrt{2} v_0^2= M/m_{Pl}, and M\sim 10^{12} GeV. A natural estimate
of Milgrom's acceleration about the Hubble rate is obtained.

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The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
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The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs