5 citations · 5 across the 5 of their papers we have counts for
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Enumeration of spanning subgraphs with degree constraints
David G. Wagner
For a finite undirected multigraph G=(V,E) and functions f,g:V-->\NN, let N_f^g(G,j) denote the number of (f,g)-factors of G with exactly j edges. The Heilmann-Lieb Theorem implies…
Remarks on one combinatorial application of the Aleksandrov-Fenchel inequalities
David G. Wagner
In 1981, Stanley applied the Aleksandrov-Fenchel inequalities to prove a logarithmic concavity theorem for regular matroids. Using ideas from electrical network theory we prove a g…
Rank three matroids are Rayleigh
David G. Wagner
A Rayleigh matroid is one which satisfies a set of inequalities analogous to the Rayleigh monotonicity property of linear resistive electrical networks. We show that every matroid…
Rayleigh Matroids
Y. -B. Choe, D. G. Wagner
Motivated by a property of linear resistive electrical networks, we introduce the class of Rayleigh matroids. This is a subclass of the balanced matroids introduced by Feder and Mi…
Homogeneous multivariate polynomials with the half-plane property
Young-Bin Choe, James G. Oxley, Alan D. Sokal +1
A polynomial P in n complex variables is said to have the "half-plane property" (or Hurwitz property) if it is nonvanishing whenever all the variables lie in the open right half-pl…
The critical group of a directed graph
David G. Wagner
The critical group K(G) of a directed graph G=(V,E) is the cokernel of the transpose of the Laplacian matrix of G acting on the integer lattice Z^V. For undirected graphs G, this h…