Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Regularized expression for the gravitational energy-momentum in
  teleparallel gravity and the principle of equivalence   The expression of the gravitational energy-momentum defined in the context of
the teleparallel equivalent of general relativity is extended to an arbitrary
set of real-valued tetrad fields, by adding a suitable reference space
subtraction term. The characterization of tetrad fields as reference frames is
addressed in the context of the Kerr space-time. It is also pointed out that
Einstein's version of the principle of equivalence does not preclude the
existence of a definition for the gravitational energy-momentum density.

25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
20
The categories of this paper are: acc-phys
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph
6
The categories of this paper are: astro-ph
2
The categories of this paper are: math
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
4
The categories of this paper are: cond-mat
35
The categories of this paper are: mtrl-th
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph