Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Probing the time-variation of the fine-structure constant: Results based
  on Si IV doublets from a UVES sample   We report a new constraint on the variation of the fine-structure constant
based on the analysis of 15 Si IV doublets selected from a ESO-UVES sample. We
find \Delta\alpha/\alpha = (+0.15+/-0.43) x 10^-5 over a redshift range of
1.59< z < 2.92 which is consistent with no variation in \alpha. This result
represents a factor of three improvement on the constraint on
\Delta\alpha/\alpha based on Si IV doublets compared to the published results
in the literature. The alkali doublet method used here avoids the implicit
assumptions used in the many-multiplet method that chemical and ionization
inhomogeneities are negligible and isotopic abundances are close to the
terrestrial value.

10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
27
The categories of this paper are: comp-gas
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
36
The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
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