Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Weyl -- Wigner -- Moyal Formalism on a Discrete Phase Space. II. The
  Photon Wigner Function   Classical model of light in helicity formalism is presented. Then quantum
point of view at photons -- construction and interpretation of photon wave
function is proposed. Quantum mechanics of photon is investigated. The Bia\l
ynicki -- Birula scalar product $\langle {\bf \Psi}_{1}|{\bf
\Psi}_{2}\rangle_{BB}$ and the generalized Hermitian conjugation
$\widehat{\gamma}^{+\hspace{-0.45em}+}$ of linear operator $\widehat{\gamma}$
are discussed. Quantum description of light on a phase space is developed. A
photon Wigner function is built.

10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
5
The categories of this paper are: gr-qc
24
The categories of this paper are: dg-ga
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
1
The categories of this paper are: cs
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
26
The categories of this paper are: bayes-an