Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: You need not be afraid of phantom energy   Phantom energy which violates the dominant-energy condition and is not
excluded by current constraints on the equation of state may be dominating the
evolution of the universe now. It has been pointed out that in such a case the
fate of the universe may be a big rid where the expansion is so violent that
all galaxies, planet and even atomic nuclei will be successively ripped apart
in finite time. Here we show however that there are certain unified models for
dark energy which are stable to perturbations in matter density where the
presence of phantom energy does not lead to such a cosmic doomsday.

21
The categories of this paper are: adap-org
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
3
The categories of this paper are: physics
17
The categories of this paper are: q-fin
5
The categories of this paper are: gr-qc
16
The categories of this paper are: stat