Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Solving the main cosmological puzzles with a generalized time varying
  vacuum energy   We study the dynamics of the FLRW flat cosmological models in which the
vacuum energy density varies with time, $\Lambda(t)$. In particular, we
investigate the dynamical properties of a generalized vacuum model and we find
that under certain conditions the vacuum term in the radiation era varies as
$\Lambda(z) \propto (1+z)^{4}$, while in the matter era we have
$\Lambda(z)\propto (1+z)^{3}$ up to $z\simeq 3$ and $\Lambda(z)=\Lambda$ for
$z\le 3$. The confirmation of such a behavior would be of paramount importance
because it could provide a solution to the cosmic coincidence problem as well
as to the fine tuning problem, without changing the well known (from the
concordance $\Lambda$ cosmology) Hubble expansion.

20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
24
The categories of this paper are: dg-ga
34
The categories of this paper are: chem-ph
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas
25
The categories of this paper are: patt-sol
3
The categories of this paper are: physics
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio