Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Constraining a scalar field dark energy with variable equation of state
  for matter   The red-shift $z_{eq}$, marking the end of radiation era and the beginning of
matter-dominated era, can play an important role to reconstruct dark-energy
models. A variable equation of state for matter that can bring a smooth
transition from radiation to matter-dominated era in a single model is proposed
to estimate $z_{eq}$ in dark energy models and hence its viability. Two
one-parameter models with minimally coupled scalar fields playing the role of
dark energy are chosen to demonstrate this point. It is found that for desired
late time behavior of the models, the estimated value of $z_{eq}$ is highly
sensitive on the value of the parameter in each of these models.

36
The categories of this paper are: cmp-lg
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
16
The categories of this paper are: stat
7
The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ