Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Gupta--Bleuler's quantization of the anisotropic parity-even and
  CPT-even electrodynamics of standard model extension   We have established the Gupta-Bleuler quantization of the photon belonging to
the anisotropic parity-even sector of the CPT-even and Lorentz-violating
nonbirefringent electrodynamics of the standard model extension. We first
present a rule for the Maxwell electrodynamics to be successfully quantized via
Gupta-Bleuler technique in the Lorentz gauge. Recognizing the failure of the
Gupta-Bleuler method in the Lorentz gauge, $\partial _{\mu }A^{\mu }=0$, for
this massless LV theory, we argue that Gupta-Bleuler can be satisfactorily
implemented by choosing a modified Lorentz condition, $\partial _{\mu }A^{\mu
}+\kappa ^{\mu \nu }\partial _{\mu }A_{\nu }=0$, where $\kappa ^{\mu \nu }$
represents the Lorentz-violation in photon sector. By using a plane-wave
expansion for the gauge field, whose polarization vectors are determined by
solving an eigenvalue problem, and a weak Gupta-Bleuler condition, we obtain a
positive-energy Hamiltonian in terms of annihilation and creation operators.
The field commutation relation is written in terms of modified Pauli-Jordan
functions, revealing the preservation of microcausality for sufficiently small
LV parameters.

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The categories of this paper are: chem-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: funct-an
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The categories of this paper are: q-alg
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The categories of this paper are: ao-sci
3
The categories of this paper are: physics
8
The categories of this paper are: hep-ex
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The categories of this paper are: quant-ph
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The categories of this paper are: supr-con
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The categories of this paper are: econ
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The categories of this paper are: chao-dyn
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The categories of this paper are: math-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: q-bio
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The categories of this paper are: acc-phys
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The categories of this paper are: q-fin