Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Radiation and vorticity: The missing link   In the context of General Relativity, radiation, either gravitational or
electromagnetic, is closely associated to vorticity of observers world lines.
We stress in this letter that the factor that relates the two phenomena is a
circular flow of energy (electromagnetic) and/or superenergy on the planes
orthogonal to vorticity vector. We also stress the potential relevance of the
abovementioned relationship in experiments to detect gravitational radiation.

33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess