Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On modular properties of odd theta-characteristics   A general canonical curve X determines a finite set T(X) of hyperplanes,
which is in bijective correspondence with the set of odd theta-characteristics
of X. The definition of T(X) can be extended to certain singular curves, in a
way that is compatible with degenerations. If X is a Deligne-Mumford stable
curve (or a cuspidal curve), we describe the enumerative and local geometry of
T(X); this is applied to show that some singular curves are uniquely determined
by T(X). This work generalizes the preliminary steps used in AG/0008239 (with
E. Sernesi) to show that a general curve of genus 3 can be recovered from its
odd theta-characteristics.

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The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
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The categories of this paper are: solv-int
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The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics
10
The categories of this paper are: q-bio
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The categories of this paper are: bayes-an
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The categories of this paper are: econ
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: funct-an
1
The categories of this paper are: cs
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The categories of this paper are: mtrl-th