| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4584603 | Journal of Algebra | 2015 | 16 Pages |
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.
Related Topics
Physical Sciences and Engineering
Mathematics
Algebra and Number Theory
Authors
Tim Netzer, Andreas Thom,