Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Theoretical calculation of the fine-structure constant and the
  permittivity of the vacuum   Light traveling through the vacuum interacts with virtual particles similarly
to the way that light traveling through a dielectric interacts with ordinary
matter. And just as the permittivity of a dielectric can be calculated, the
permittivity $\epsilon_0$ of the vacuum can be calculated, yielding an equation
for the fine-structure constant $\alpha$. The most important contributions to
the value of $\alpha$ arise from interactions in the vacuum of photons with
virtual, bound states of charged lepton-antilepton pairs. Considering only
these contributions, the fully screened $\alpha \cong 1/(8^2\sqrt{3\pi/2})
\cong 1/139$.

4
The categories of this paper are: cond-mat
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph
36
The categories of this paper are: cmp-lg
24
The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
26
The categories of this paper are: bayes-an