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arXiv · 1310.6903

Positivstellensätze for Quantum Multigraphs

Tim Netzer·Andreas Thom
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Abstract

Studying inequalities between subgraph- or homomorphism-densities is an important topic in graph theory. Sums of squares techniques have proven useful in dealing with such questions. Using an approach from real algebraic geometry, we strengthen a Positivstellensatz for simple quantum graphs by Lovász and Szegedy, and we prove several new Positivstellensätze for nonnegativity of quantum multigraphs. We provide new examples and counterexamples.

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Tim Netzer, Andreas Thom. 2013-10-25. Positivstellensätze for Quantum Multigraphs. https://arxiv.org/abs/1310.6903

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