Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Need of Dark Energy for Dynamical Compactification of Extra
  Dimensions on the Brane   We consider a six-dimensional braneworld model and we study the cosmological
evolution of a (4+1) brane-universe. Introducing matter on the brane we show
that the scale factor of the physical three-dimensional brane-universe is
related to the scale factor of the fourth dimension on the brane, and the
suppression of the extra dimension compared to the three dimensions requires
the presence of dark energy.

26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
3
The categories of this paper are: physics
8
The categories of this paper are: hep-ex
4
The categories of this paper are: cond-mat
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org