Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A solution for the cosmological constant problem   We consider that the cosmological constant is associated with the vacuum
energy density of a particle physics model. In the path integral formalism of
euclidean quantum gravity and in the background of the Robertson Walker metric
we calculate only the contribution of the matter density to the fluctuating
metric. This produces an effective term in the action that acts as a correction
to the vacuum energy density of the matter. The method leads to the observed
cosmological constant without the need of any fine tuning in the gravity or
particle physics sectors.

6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
2
The categories of this paper are: math
19
The categories of this paper are: eess
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
21
The categories of this paper are: adap-org