An extension of matroid rank submodularity and the \(Z\)-Rayleigh property
The electronic journal of combinatorics, Tome 18 (2011) no. 1
We define an extension of matroid rank submodularity called $R$-submodularity, and introduce a minor-closed class of matroids called extended submodular matroids that are well-behaved with respect to $R$-submodularity. We apply $R$-submodularity to study a class of matroids with negatively correlated multivariate Tutte polynomials called the $Z$-Rayleigh matroids. First, we show that the class of extended submodular matroids are $Z$-Rayleigh. Second, we characterize a minor-minimal non-$Z$-Rayleigh matroid using its $R$-submodular properties. Lastly, we use $R$-submodularity to show that the Fano and non-Fano matroids (neither of which is extended submodular) are $Z$-Rayleigh, thus giving the first known examples of $Z$-Rayleigh matroids without the half-plane property.
DOI :
10.37236/600
Classification :
05B35
Mots-clés : \(R\)-submodularity, extended submodular matroids
Mots-clés : \(R\)-submodularity, extended submodular matroids
@article{10_37236_600,
author = {Arun P. Mani},
title = {An extension of matroid rank submodularity and the {\(Z\)-Rayleigh} property},
journal = {The electronic journal of combinatorics},
year = {2011},
volume = {18},
number = {1},
doi = {10.37236/600},
zbl = {1233.05078},
url = {http://geodesic.mathdoc.fr/articles/10.37236/600/}
}
Arun P. Mani. An extension of matroid rank submodularity and the \(Z\)-Rayleigh property. The electronic journal of combinatorics, Tome 18 (2011) no. 1. doi: 10.37236/600
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