Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Tests of the Lorentz and CPT Symmetries at the Planck Energy Scale with
  X-Ray and Gamma-Ray Observations   X-ray and gamma-ray observations of astrophysical objects at cosmological
distances can be used to probe the energy dependence of the speed of light with
high accuracy and to search for violations of Lorentz invariance and CPT
symmetry at the Planck energy scale. In this conference contribution, we
discuss these searches in the theoretical framework of the Standard-Model
Extension. We present new limits on the dispersion relation governed by
operators of mass dimension d=5 and d=6, and we discuss avenues for future
progress.

10
The categories of this paper are: q-bio
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org