Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quintessential inflation from a variable cosmological constant in a 5D
  vacuum   We explore an effective 4D cosmological model for the universe where the
variable cosmological constant governs its evolution and the pressure remains
negative along all the expansion. This model is introduced from a 5D vacuum
state where the (space-like) extra coordinate is considered as noncompact. The
expansion is produced by the inflaton field, which is considered as
nonminimally coupled to gravity. We conclude from experiental data that the
coupling of the inflaton with gravity should be weak, but variable in different
epochs of the evolution of the universe.

30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
23
The categories of this paper are: solv-int
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
3
The categories of this paper are: physics
25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
4
The categories of this paper are: cond-mat
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an