Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Are there MACHOs in the Milky Way halo?   Microlensing searches aim to detect compact halo dark matter via its
gravitational lensing effect on stars within the Large Magellanic Cloud. The
most recent results have led to the claim that roughly one fifth of the
galactic halo dark matter may be in the form of compact, solar-mass objects. We
analyze this hypothesis by considering the goodness-of-fit of the best-fit halo
dark matter solutions to the observational data. We show that the distribution
of the durations of the observed microlensing events is narrower than that
expected to result from a standard halo lens population at 90 to 95%
confidence. Only when the fraction of expected background (non-halo) events is
significantly increased does the discrepancy between the observed and
theoretical event duration distributions disappear. This indicates that it is
possible that most of the lenses responsible for the observed microlensing
events are not located within the Milky Way halo.

9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat
18
The categories of this paper are: econ
0
The categories of this paper are: hep-ph
22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
36
The categories of this paper are: cmp-lg
8
The categories of this paper are: hep-ex
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
5
The categories of this paper are: gr-qc
28
The categories of this paper are: alg-geom