Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Elastic Orbital Angular Momentum   We identify that flexural guided elastic waves in elastic pipes carry a
well-defined orbital angular momentum associated with the compressional
dilatational potential. This enables the transfer of elastic orbital angular
momentum, that we numerically demonstrate, through the coupling of the
compressional potential in a pipe to the acoustic pressure field in a
surrounding fluid in contact with the pipe.

6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ