Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: True wavefunctions and antiparticles of Klein-Gordon equation:
  $\hbar$-conjugation, elimination of $CPT$-invariance, and anti-gravitation   While revisiting Klein-Gordon relativistic quantum equation for spin-0
particles, we predicted that $\hbar$ reverses its sign for negative energies,
and formulated a universal symmetry rule, whereby all the parameters that
couple particles to external fields reverse their sign along with $\hbar$ at a
particle$\leftrightarrow$antiparticle transformation; this in particular
implies anti-gravitation between matter and antimatter. Our results suggest
that the $\hbar$-conjugation principle and related invariance may replace
$CPT$-invariance in general relativistic quantum mechanics.

18
The categories of this paper are: econ
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
14
The categories of this paper are: math-ph
35
The categories of this paper are: mtrl-th
2
The categories of this paper are: math
22
The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
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The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio