Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Symmetric vacuum scalar--tensor cosmology   The existence of point symmetries in the cosmological field equations of
generalized vacuum scalar--tensor theories is considered within the context of
the spatially homogeneous cosmologies. It is found that such symmetries only
occur in the Brans--Dicke theory when the dilaton field self--interacts.
Moreover, the interaction potential of the dilaton must take the form of a
cosmological constant. For the spatially flat, isotropic model, it is shown how
this point symmetry may be employed to generate a discrete scale factor duality
in the Brans--Dicke action.

27
The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs
4
The categories of this paper are: cond-mat
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
19
The categories of this paper are: eess
7
The categories of this paper are: hep-th
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph
2
The categories of this paper are: math