4 papers · 1 filter
Excluded conformal minors of Birkhoff-von Neumann graphs with equal global forcing number and maximum anti-forcing number
Yaxian Zhang, Yan Wu, Heping Zhang
Global forcing number and maximum anti-forcing number of matchable graphs (graphs with a perfect matching) were proposed in completely different situations with applications in the…
The maximum forcing numbers of quadriculated tori
Qianqian Liu, Yaxian Zhang, Heping Zhang
Klein and Randic (1985) proposed the concept of forcing number, which has an application in chemical resonance theory. Let be a graph with a perfect matching . The forcing n…
Cubic bricks that every b-invariant edge is forcing
Yaxian Zhang, Fuliang Lu, Heping Zhang
A connected graph G is matching covered if every edge lies in some perfect matching of G. Lovasz proved that every matching covered graph G can be uniquely decomposed into a list o…
Components of domino tilings under flips in quadriculated tori
Qianqian Liu, Yaxian Zhang, Heping Zhang
In a region R consisting of unit squares, a (domino) tiling is a collection of dominoes (the union of two adjacent squares) which pave fully the region. The flip graph of R is defi…