Neighborhood union conditions for fractional [a, b]-covered graphs
Tóm tắt
Let G be a graph of order n. The binding number $$\text{ bind }(G)$$ of G is $$\min \{\frac{|N_{G}(X)|}{|X|}\mid \emptyset \ne X\subseteq V(G)\,\, \text{ and }\,\, N_{G}(X)\ne V(G)\}$$. Throughout this article, some sufficient conditions about neighborhood union and $$\text{ bind }(G)$$ for a graph G to be fractional covered are obtained. Moreover, some graphs to verify that the results are best possible in a certain sense are gotten.
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