Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Entropy flow of a perfect fluid in (1+1) hydrodynamics   Using the formalism of the Khalatnikov potential, we derive exact general
formulae for the entropy flow dS/dy, where y is the rapidity, as a function of
temperature for the (1+1) relativistic hydrodynamics of a perfect fluid. We
study in particular flows dominated by a sufficiently long hydrodynamic
evolution, and provide an explicit analytical solution for dS/dy. We discuss
the theoretical implications of our general formulae and some phenomenological
applications for heavy-ion collisions.

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The categories of this paper are: alg-geom
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The categories of this paper are: q-fin
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
26
The categories of this paper are: bayes-an
24
The categories of this paper are: dg-ga
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The categories of this paper are: plasm-ph
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The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat
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The categories of this paper are: eess
8
The categories of this paper are: hep-ex
20
The categories of this paper are: acc-phys
18
The categories of this paper are: econ
6
The categories of this paper are: astro-ph