Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Long Range Effects of Cosmic String Structure   We combine and further develop ideas and techniques of Allen \& Ottewill,
Phys. Rev.D, {\bf 42}, 2669 (1990) and Kay \& Studer Commun. Math. Phys., {\bf
139}, 103 (1991) for calculating the long range effects of cosmic string cores
on classical and quantum field quantities far from an (infinitely long,
straight) cosmic string. We find analytical approximations for (a) the
gravity-induced ground state renormalized expectation values of $\hat\varphi^2$
and $\hat T_\mu{}^\nu$ for a non-minimally coupled quantum scalar field far
from a cosmic string (b) the classical electrostatic self force on a test
charge far from a superconducting cosmic string. Surprisingly -- even at
cosmologically large distances -- all these quantities would be very badly
approximated by idealizing the string as having zero thickness and imposing
regular boundary conditions; instead they are well approximated by suitably
fitted strengths of logarithmic divergence at the string core. Our formula for
${\langle {\hat \varphi}^2 \rangle}$ reproduces (with much less effort and much
more generality) the earlier numerical results of Allen \& Ottewill. Both
${\langle {\hat \varphi}^2 \rangle}$ and ${\langle {\hat T}_{\mu}{}^{\nu}
\rangle}$ turn out to be ``weak field topological invariants'' depending on the
details of the string core only through the minimal coupling parameter
``$\xi$'' (and the deficit angle). Our formula for the self-force (leaving
aside relatively tiny gravitational corrections) turns out to be attractive: We
obtain, for the self-potential of a test charge $Q$ a distance $r$ from a (GUT
scale) superconducting string, the formula $- Q^2/(16\epsilon_0r\ln(qr))$ where
$q$ is an (in principle, computable) constant of the order of the inverse
string radius.

30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
4
The categories of this paper are: cond-mat
35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
3
The categories of this paper are: physics