Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Note on the Convex Hull of Finitely Many Projections of Spectrahedra   A spectrahedron is a set defined by a linear matrix inequality. A projection
of a spectrahedron is often called a semidefinitely representable set. We show
that the convex hull of a finite union of such projections is again a
projection of a spectrahedron. This improves upon the result of Helton and Nie,
who prove the same result in the case of bounded sets.

15
The categories of this paper are: nucl-ex
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The categories of this paper are: acc-phys
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The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
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The categories of this paper are: solv-int
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The categories of this paper are: nlin
3
The categories of this paper are: physics
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The categories of this paper are: comp-gas
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The categories of this paper are: eess
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The categories of this paper are: cmp-lg
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The categories of this paper are: dg-ga
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The categories of this paper are: q-fin