Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Feynman graphs and related Hopf algebras   In a recent series of communications we have shown that the reordering
problem of bosons leads to certain combinatorial structures. These structures
may be associated with a certain graphical description. In this paper, we show
that there is a Hopf Algebra structure associated with this problem which is,
in a certain sense, unique.

15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
16
The categories of this paper are: stat
3
The categories of this paper are: physics
7
The categories of this paper are: hep-th
6
The categories of this paper are: astro-ph
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int