Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Euler Characteristics of Moduli Spaces of Curves   Let ${mathcal M}_g^n$ be the moduli space of n-pointed Riemann surfaces of
genus g. Denote by ${\bar {\mathcal M}}_g^n$ the Deligne-Mumford
compactification of ${mathcal M}_g^n$. In the present paper, we calculate the
orbifold and the ordinary Euler characteristic of ${\bar {\mathcal M}}_g^n$ for
any g and n such that n>2-2g.

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The categories of this paper are: physics
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The categories of this paper are: funct-an
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The categories of this paper are: eess
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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: hep-th
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The categories of this paper are: nlin
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-ex
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The categories of this paper are: bayes-an
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The categories of this paper are: supr-con
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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: q-bio
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The categories of this paper are: adap-org
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The categories of this paper are: comp-gas