Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spontaneous Breaking of Lorentz Symmetry with an antisymmetric tensor   Spontaneous violation of Lorentz symmetry by the vacuum condensation of an
antisymmetric $2$-tensor is considered. The coset construction for nonlinear
realization of spacetime symmetries is employed to build the most general
low-energy effective action for the Goldstone modes interacting with photons.
We analyze the model within the context of the Standard-Model Extension and
noncommutative QED. Experimental bounds for some parameters of the model are
discussed, and we readdress the subtle issues of stability and causality in
Lorentz non-invariant scenarios. Besides the two photon polarizations, just one
Goldstone mode must be dynamical to set a sensible low-energy effective model,
and the enhancement of the stability by accounting interaction terms points to
a protection against observational Lorentz violation.

35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
31
The categories of this paper are: ao-sci
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas