Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: FRW Universe Models in Conformally Flat Spacetime Coordinates. III:
  Universe models with positive spatial curvature   We deduce general expressions for the line element of universe models with
positive spatial curvature described by conformally flat spacetime coordinates.
Models with dust, radiation and vacuum energy are exhibited. Discussing the
existence of particle horizons we show that there is continual annihilation of
space, matter and energy in a dust and radiation dominated universe, and
continual creation in a LIVE domined universe when conformal time is used in
Friedmann-Robertson-Walker models with positive spatial curvature. A general
procedure is given for finding coordinates to be used in Penrose diagrams. We
also calculate the age and the redshift of some universe models using conformal
time.

11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
24
The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
3
The categories of this paper are: physics
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an