Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Estimating Energy-Momentum and Angular Momentum Near Null Infinity   The energy-momentum and angular momentum contained in a spacelike two-surface
of spherical topology are estimated by joining the two-surface to null infinity
via an approximate no-incoming-radiation condition. The result is a set of
gauge-invariant formulas for energy-momentum and angular momentum which should
be applicable to much numerical work; it also gives estimates of the
finite-size effects.

26
The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
24
The categories of this paper are: dg-ga
27
The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph
23
The categories of this paper are: solv-int
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con