5 citations · 5 across the 4 of their papers we have counts for
4 papers
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…
Correction to a theorem of Schoenberg
Carl Johan Ragnarsson, Wesley Wai Suen, David G. Wagner
A well-known theorem of Schoenberg states that if f(z) generates a PF_r sequence then 1/f(-z) generates a PF_r sequence. We give two counterexamples which show that this is not tru…
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…