Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A new kind of cyclic universe   Combining intervals of ekpyrotic (ultra-slow) contraction with a
(non-singular) classical bounce naturally leads to a novel cyclic theory of the
universe in which the Hubble parameter, energy density and temperature
oscillate periodically, but the scale factor grows by an exponential factor
from one cycle to the next. The resulting cosmology not only resolves the
homogeneity, isotropy, flatness and monopole problems and generates a nearly
scale invariant spectrum of density perturbations, but it also addresses a
number of age-old cosmological issues that big bang inflationary cosmology does
not. There may also be wider-ranging implications for fundamental physics,
black holes and quantum measurement.

29
The categories of this paper are: funct-an
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
22
The categories of this paper are: chao-dyn
12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph