Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dirac canonical idea as an alternative to the approach of Bohr. A toy
  model   Classical objects have been excluded as subjects of the observed quantum
properties, and the related problem of quantum objects nature has been
suspended since the early days of Quantum Theory. Recent experiments show that
the problem could be reasonably revisited. The outlined model indicates new
issues, which could result from following and exploring the canonical idea of
Dirac. Topological defects in solids are considered as an example. The aim is
helping to grasp the underlying pre-theoretical new intuitions, which should
replace the old ones attached to the background of classical physics.

33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
22
The categories of this paper are: chao-dyn
34
The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
18
The categories of this paper are: econ
29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
8
The categories of this paper are: hep-ex
10
The categories of this paper are: q-bio