论文标题
边界莫斯塔尔指数
Bounding the Mostar index
论文作者
论文摘要
Došlić等。 defined the Mostar index of a graph $G$ as $Mo(G)=\sum\limits_{uv\in E(G)}|n_G(u,v)-n_G(v,u)|$, where, for an edge $uv$ of $G$, the term $n_G(u,v)$ denotes the number of vertices of $G$ that have a smaller distance in $G$ to $u$ than to $ V $。他们推测$ mo(g)\ leq 0. \ + overline {148} n^3 $对于订单$ n $的每个图$ g $。作为Mostar索引上的自然上限,Geneson和Tsai隐含地考虑参数$ MO^\ star(g)= \ sum \ limits_ {uv \ in E(g)} \ big big(n- \ min \ {d_g(d_g(d_g(u))对于订单$ n $的图$ g $,他们表明$ mo^\ star(g)\ leq \ frac {5} {24}(1+o(1))n^3 $。 我们将此绑定到$ mo^\ star(g)\ leq \ left(\ frac {2} {\ sqrt {3}}}} - 1 \ right)n^3 $,这是最好的较低顺序。此外,我们表明$ mo^\ star(g)\ leq \ left(2 \ left(\fracδ{n} \ right)^2+\左(\fracδ{n} \ right)-2 \ left(\fracΔ{n} \ right)\ sqrt {\ left(\fracδ{n} \ right)^2+\ left(\fracδ{n} \ right)} \ right)n^3 $前提是$ g $具有最高度$δ$。
Došlić et al. defined the Mostar index of a graph $G$ as $Mo(G)=\sum\limits_{uv\in E(G)}|n_G(u,v)-n_G(v,u)|$, where, for an edge $uv$ of $G$, the term $n_G(u,v)$ denotes the number of vertices of $G$ that have a smaller distance in $G$ to $u$ than to $v$. They conjectured that $Mo(G)\leq 0.\overline{148}n^3$ for every graph $G$ of order $n$. As a natural upper bound on the Mostar index, Geneson and Tsai implicitly consider the parameter $Mo^\star(G)=\sum\limits_{uv\in E(G)}\big(n-\min\{ d_G(u),d_G(v)\}\big)$. For a graph $G$ of order $n$, they show that $Mo^\star(G)\leq \frac{5}{24}(1+o(1))n^3$. We improve this bound to $Mo^\star(G)\leq \left(\frac{2}{\sqrt{3}}-1\right)n^3$, which is best possible up to terms of lower order. Furthermore, we show that $Mo^\star(G)\leq \left(2\left(\fracΔ{n}\right)^2+\left(\fracΔ{n}\right)-2\left(\fracΔ{n}\right)\sqrt{\left(\fracΔ{n}\right)^2+\left(\fracΔ{n}\right)}\right)n^3$ provided that $G$ has maximum degree $Δ$.