Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Scaling Dark Energy in a Five-Dimensional Bouncing Cosmological Model   We consider a 5-dimensional Ricci flat bouncing cosmological model in which
the 4-dimensional induced matter contains two components at late times - the
cold dark matter (CDM)+baryons and dark energy. We find that the arbitrary
function $f(z)$ contained in the solution plays a similar role as the potential
$V(\phi)$ in quintessence and phantom dark energy models. To resolve the
coincidence problem, it is generally believed that there is a scaling stage in
the evolution of the universe. We analyze the condition for this stage and show
that a hyperbolic form of the function $f(z)$ can work well in this property.
We find that during the scaling stage (before $z\approx 2$), the dark energy
behaves like (but not identical to) a cold dark matter with an adiabatic sound
speed $c_{s}^{2}\approx 0$ and $p_{x}\approx 0$. After $z\approx 2$, the
pressure of dark energy becomes negative. The transition from deceleration to
acceleration happens at $z_{T}\approx 0.8$ which, as well as other predictions
of the $5D$ model, agree with current observations.

28
The categories of this paper are: alg-geom
4
The categories of this paper are: cond-mat
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc
26
The categories of this paper are: bayes-an
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
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The categories of this paper are: eess
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg