Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Variation of fundamental constants: theory and observations   Review of recent works devoted to the variation of the fundamental constants
is presented including atomic clocks, quasar absorption spectra, and Oklo
natural nuclear reactor data. Assuming linear variation with time we can
compare different results. From the quasar absorption spectra:
  $\dot{\mu}/\mu=(1 \pm 3) \times 10^{-16}$ yr$^{-1}$. A combination of this
result and the atomic clock results gives the best limt on variation of
$\alpha$: $\dot{\alpha}/\alpha=(-0.8 \pm 0.8) \times 10^{-16}$ yr$^{-1}$. The
Oklo natural reactor gives the best limit on the variation of
$m_s/\Lambda_{QCD}$ where $m_s$ is the strange quark mass.
  Huge enhancement of the relative variation effects happens in transitions
between close atomic, molecular and nuclear energy levels. We suggest several
new cases where the levels are very narrow. Large enhancement of the variation
effects is also possible in cold atomic and molecular collisions near Feshbach
resonance. Massive bodies (stars or galaxies) can also affect physical
constants. They have large scalar charge $S$ proportional to number of
particles which produces a Coulomb-like scalar field $U=S/r$. This leads to a
variation of the fundamental constants proportional to the gravitational
potential, e.g. $\delta \alpha/ \alpha = k_\alpha \delta (GM/ r c^2)$. We
compare different manifestations of this effect.The strongest limit
  $k_\alpha +0.17 k_e= (-3.5\pm 6) \times 10^{-7}$.

35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
22
The categories of this paper are: chao-dyn
36
The categories of this paper are: cmp-lg
1
The categories of this paper are: cs
4
The categories of this paper are: cond-mat
9
The categories of this paper are: nlin
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con