Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Two viable quintessence models of the Universe: confrontation of
  theoretical predictions with observational data   We use some of the recently released observational data to test the viability
of two classes of minimally coupled scalar field models of quintessence with
exponential potentials for which exact solutions of the Einstein equations are
known. These models are very sturdy, depending on only one parameter - the
Hubble constant. To compare predictions of our models with observations we
concentrate on the following data: the power spectrum of the CMBR anisotropy as
measured by WMAP, the publicly available data on type Ia supernovae, and the
parameters of large scale structure determined by the 2-degree Field Galaxy
Redshift Survey (2dFGRS). We use the WMAP data on the age of the universe and
the Hubble constant to fix the free parameters in our models. We then show that
the predictions of our models are consistent with the observed positions and
relative heights of the first 3 peaks in the CMB power spectrum, with the
energy density of dark energy as deduced from observations of distant type Ia
supernovae, and with parameters of the large scale structure as determined by
2dFGRS, in particular with the average density of dark matter. Our models are
also consistent with the results of the Sloan Digital Sky Survey (SDSS).
Moreover, we investigate the evolution of matter density perturbations in our
quintessential models, solve exactly the evolution equation for the density
perturbations, and obtain an analytical expression for the growth index $f$. We
verify that the approximate relation f ~ Omega_M^(alpha) also holds in our
models.

17
The categories of this paper are: q-fin
24
The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc