Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Scale-factor duality in string Bianchi cosmologies   We apply the scale factor duality transformations introduced in the context
of the effective string theory to the anisotropic Bianchi-type models. We find
dual models for all the Bianchi-types [except for types $VIII$ and $IX$] and
construct for each of them its explicit form starting from the exact original
solution of the field equations. It is emphasized that the dual Bianchi class
$B$ models require the loss of the initial homogeneity symmetry of the
dilatonic scalar field.

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The categories of this paper are: econ
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The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph
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The categories of this paper are: q-bio
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The categories of this paper are: hep-lat
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The categories of this paper are: eess
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The categories of this paper are: acc-phys
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The categories of this paper are: alg-geom
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The categories of this paper are: comp-gas
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The categories of this paper are: hep-ex
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The categories of this paper are: physics
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The categories of this paper are: mtrl-th
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The categories of this paper are: cs
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The categories of this paper are: quant-ph
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The categories of this paper are: solv-int