Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The direct link model for polymer rings as a topological field theory
  and the second topological moment in dense systems   Polymer rings in solution are either permanently entangled or not. Permanent
topological restrictions give rise to additional entropic interactions apart
from the ones arising due to mere chain flexibility or excluded volume.
Conversely, entangled polymer rings systems may be formed by closing randomly
entangled flexible linear chains. The dependance of linking numbers between
randomly entangled rings on the chain length, more specifically the second
topological moment $<n^2>$, i.e. the average squared linking number, may be
determined. In this paper, an approach recently discussed in mathematical
physics and called abelian BF theory, is presented which allows to express the
linking constraint in its simplest form, the Gauss integral, in terms of two
gauge fields. The model of Brereton and Shah for a single ring entangled with
many other surrounding rings is rederived. The latter model is finally used to
calculate the second topological moment, in agreement with a recent result by
Ferrari, Kleinert, and Lazzizzera obtained by using ${\rm n}$-component
$\phi^4$ theory in the limit ${\rm n}\to 0$.

35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
23
The categories of this paper are: solv-int
26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex