Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Evolution of a global string network in a matter dominated universe   We evolve the network of global strings in the matter-dominated universe by
means of numerical simulations. The existence of the scaling solution is
confirmed as in the radiation-dominated universe but the scaling parameter
$\xi$ takes a slightly smaller value, $\xi \simeq 0.6 \pm 0.1$, which is
defined as $\xi = \rho_{s} t^{2} / \mu$ with $\rho_{s}$ the energy density of
global strings and $\mu$ the string tension per unit length. The change of
$\xi$ from the radiation to the matter-dominated universe is consistent with
that obtained by Albrecht and Turok by use of the one-scale model. We also
study the loop distribution function and find that it can be well fitted with
that predicted by the one-scale model, where the number density $n_{l}(t)$ of
the loop with the length $l$ is given by $n_{l}(t) = \nu/[t^2 (l + \kappa
t)^2]$ with $\nu \sim 0.040$ and $\kappa \sim 0.48$. Thus, the evolution of the
global string network in the matter-dominated universe can be well described by
the one-scale model as in the radiation-dominated universe.

30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
7
The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex