Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Solvable Many-Body Models of Goldfish Type with One-, Two- and
  Three-Body Forces   The class of solvable many-body problems "of goldfish type" is extended by
including (the additional presence of) three-body forces. The solvable $N$-body
problems thereby identified are characterized by Newtonian equations of motion
featuring 19 arbitrary "coupling constants". Restrictions on these constants
are identified which cause these systems - or appropriate variants of them - to
be isochronous or asymptotically isochronous, i.e. all their solutions to be
periodic with a fixed period (independent of the initial data) or to have this
property up to contributions vanishing exponentially as $t\rightarrow\infty$.

3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
17
The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
13
The categories of this paper are: quant-ph
24
The categories of this paper are: dg-ga
27
The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg