Relations between global forcing number and maximum anti-forcing number of a graph
نویسندگان
چکیده
The global forcing number of a graph G is the minimal cardinality an edge subset discriminating all perfect matchings G, denoted by gf(G). For matching M S⊆E(G)∖M such that G−S has unique called anti-forcing M. maximum among Af(G). It known hexagonal system equals famous Fries number. bipartite we show gf(G)≥Af(G). Next extend result to Birkhoff–von Neumann graphs, whose polytopes are characterized solely nonnegativity and degree constraints, revealing odd dumbbell non-bipartite graphs with minimum at least two. Finally, obtain tight upper lower bounds on gf(G)−Af(G). connected 2n vertices, 0≤gf(G)−Af(G)≤12(n−1)(n−2). case, have −Occ(G)≤gf(G)−Af(G)≤(n−1)(n−2) introducing new nonnegative parameter Occ(G).
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ژورنال
عنوان ژورنال: Discrete Applied Mathematics
سال: 2022
ISSN: ['1872-6771', '0166-218X']
DOI: https://doi.org/10.1016/j.dam.2022.01.010