Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Space-time curvature due to quantum vacuum fluctuations: An alternative
  to dark energy?   It is pointed out that quantum vacuum fluctuations may give rise to a
curvature of space-time equivalent to the curvature currently attributed to
dark energy. A simple calculation is made, which suggests that the value of the
dark energy density is roughly given by the product of Newton constant time the
quantity m^6 c^4 h^-4, m being a typical mass of elementary particles. The
estimate is compatible with observations.

15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg
26
The categories of this paper are: bayes-an
16
The categories of this paper are: stat
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin
29
The categories of this paper are: funct-an