Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Macroscopic observables and Lorentz violation in discrete quantum
  gravity   This article concerns the fate of local Lorentz invariance in quantum
gravity, particularly for approaches in which a discrete structure replaces
continuum spacetime. Some features of standard quantum mechanics, presented in
a sum-over-histories formulation, are reviewed, and their consequences for such
theories are discussed. It is argued that, if the individual histories of a
theory give bad approximations to macroscopic continuum properties in some
frames, then it is inevitable that the theory violates Lorentz symmetry.

1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
22
The categories of this paper are: chao-dyn
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
2
The categories of this paper are: math
3
The categories of this paper are: physics