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Joonkyung Lee (이준경), Counting homomorphisms in antiferromagnetic graphs via Lorentzian polynomials
Joonkyung Lee (이준경), Counting homomorphisms in antiferromagnetic graphs via Lorentzian polynomials
An edge-weighted graph $G$, possibly with loops, is said to be antiferromagnetic if it has nonnegative weights and at most one positive eigenvalue, counting multiplicities. The number of graph homomorphisms from a graph $H$ to an antiferromagnetic graph $G$ generalises various important parameters in graph theory, including the number of independent sets and proper vertex …