Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Characterizing N+-perfect line graphs   The subject of this contribution is the study of the Lov\'asz-Schrijver
PSD-operator N+ applied to the edge relaxation of the stable set polytope of a
graph. We are particularly interested in the problem of characterizing graphs
for which N+ generates the stable set polytope in one step, called N+-perfect
graphs. It is conjectured that the only N+-perfect graphs are those whose
stable set polytope is described by inequalities with near-bipartite support.
So far, this conjecture has been proved for near-perfect graphs, fs-perfect
graphs, and webs. Here, we verify it for line graphs, by proving that in an
N+-perfect line graph the only facet-defining graphs are cliques and odd holes.

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The categories of this paper are: astro-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: math-ph
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The categories of this paper are: adap-org
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The categories of this paper are: nlin
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The categories of this paper are: hep-lat
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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: nucl-th
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The categories of this paper are: stat
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The categories of this paper are: solv-int
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The categories of this paper are: patt-sol
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The categories of this paper are: ao-sci
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The categories of this paper are: atom-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: cmp-lg