Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: O(d,d) invariance at two and three loops   We show that in a two-dimensional sigma-model whose fields only depend on one
target space co-ordinate, the O(d,d) invariance of the conformal invariance
conditions observed at one loop is preserved at two loops (in the general case
with torsion) and at three loops (in the case without torsion).

9
The categories of this paper are: nlin
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The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: comp-gas
1
The categories of this paper are: cs
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The categories of this paper are: stat
34
The categories of this paper are: chem-ph
25
The categories of this paper are: patt-sol
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The categories of this paper are: math-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: solv-int
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The categories of this paper are: cond-mat
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The categories of this paper are: ao-sci
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The categories of this paper are: astro-ph
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The categories of this paper are: cmp-lg