Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the SU(1,1) Thermal Group of Bosonic Strings and D-Branes   All possible Bogoliubov operators that generate the thermal transformations
in the Thermo Field Dynamics (TFD) form a SU(1,1) group. We discuss this
contruction in the bosonic string theory. In particular, the transformation of
the Fock space and string operators generated by the most general SU(1,1)
unitary Bogoliubov transformation and the entropy of the corresponding thermal
string are computed. Also, we construct the thermal $D$-brane solution
generated by the SU(1,1) transformation in a constant Kalb-Ramond field and
compute its entropy.

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The categories of this paper are: dg-ga
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The categories of this paper are: acc-phys
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The categories of this paper are: ao-sci
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The categories of this paper are: q-alg
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The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
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The categories of this paper are: solv-int
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The categories of this paper are: nucl-ex
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The categories of this paper are: bayes-an
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The categories of this paper are: patt-sol
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The categories of this paper are: math
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The categories of this paper are: quant-ph
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The categories of this paper are: eess
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The categories of this paper are: nlin
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The categories of this paper are: chem-ph
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The categories of this paper are: nucl-th