Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Flux compactifications, twisted tori and doubled geometry   In arXiv:0902.4032 [hep-th] an O(D,D)-covariant sigma model describing the
embedding of a closed world-sheet into the 2D-dimensional twisted torus was
proposed. Such sigma models provide a universal description of string theory
with target spaces related by the action of T-duality. In this article a
six-dimensional toy example is studied in detail. Different polarisations of
the six-dimensional target space give different three-dimensional string
backgrounds including a nilmanifold with H-flux, a T-fold with R-flux and a new
class of T-folds. Global issues and connections with the doubled torus
formalism are discussed. Finally, the sigma model introduced in arXiv:0902.4032
[hep-th], describing the embedding of a world-sheet into the doubled twisted
torus, is generalised to one describing a target space which is a bundle of the
doubled twisted torus over a base, allowing for a more complete description of
the associated gauged supergravity from the world-sheet perspective to be
given.

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The categories of this paper are: physics
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The categories of this paper are: stat
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The categories of this paper are: cond-mat
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The categories of this paper are: nucl-ex
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The categories of this paper are: q-bio
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The categories of this paper are: eess
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The categories of this paper are: math
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The categories of this paper are: astro-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: quant-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: solv-int
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The categories of this paper are: cs
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The categories of this paper are: alg-geom
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The categories of this paper are: ao-sci
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The categories of this paper are: q-fin