فهرست نشریات علمی دسترسی آزاد ایران

For a graph $G$ with vertices colored either black or white, consider the following rule to change the colors: the color of a vertex which is the only white neighbor of a black vertex, changes from white to black. A proper subset $S$ of the vertex set of $G$ is called a failed zero forcing set if, regardless of how many times this rule is applied to a graph with the initial black vertices $S$, at least one white vertex always remains. The maximum size of such a subset is called the failed zero forcing number of $G$ and is denoted by $F(G)$. In this paper, we look at the failed zero forcing numbers of Grassmann graphs $J_q(n, 2)$ and prove that $F(J_q(n, 2))={n \brack 2}_q - b'_2(q)$, for $n\geq 5$, where $b'_2(q)$ is the maximum number of points in the affine or projective plane of order $q$ such that there is no line that passes through exactly one of these points. Moreover, using maximum arcs in the projective planes, we show that if $q$ is a power of two, then $F(J_q(n, 2))={n \brack 2}_q - (q + 2)$.