Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Are All Particles Real?   In Bohmian mechanics elementary particles exist objectively, as point
particles moving according to a law determined by a wavefunction. In this
context, questions as to whether the particles of a certain species are
real--questions such as, Do photons exist? Electrons? Or just the quarks?--have
a clear meaning. We explain that, whatever the answer, there is a corresponding
Bohm-type theory, and no experiment can ever decide between these theories.
Another question that has a clear meaning is whether particles are
intrinsically distinguishable, i.e., whether particle world lines have labels
indicating the species. We discuss the intriguing possibility that the answer
is no, and particles are points--just points.

35
The categories of this paper are: mtrl-th
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
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The categories of this paper are: eess
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
28
The categories of this paper are: alg-geom