Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the Study of the Substructure of N-body Systems   Statistical properties of nonlinear systems revealed in an unexpected way
already in Fermi-Pasta-Ulam paper, are responsible for the appearance of
substructures. We represent a method within S-tree diagram formalism for
investigation of the substructures of N-body gravitating systems in a defined
time interval. This approach enables one to consider the link between
substructures of the system and its relative instability and is efficient for
the study of the substructures in clusters of galaxies.

14
The categories of this paper are: math-ph
27
The categories of this paper are: comp-gas
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
19
The categories of this paper are: eess
5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
28
The categories of this paper are: alg-geom
32
The categories of this paper are: atom-ph
3
The categories of this paper are: physics