Total Irregularity and $f_t$-Irregularity of Linear Jaco Graphs$

Abstract

Total irregularity of a simple undirected graph $G$ is defined to be $ir{r}_t(G)=\frac{1}{2}\sum _{u,v\in V(G)}|d(u)-d(v)|$. See Abdo and Dimitrov [2]. We allocate the \emph{Fibonacci weight,} $f_i$ to a vertex $v_j$ of a simple connected graph, if and only if $d(v_j)=i$ and define the \emph{total fibonaccian irregularity} or $f_t-irregularity$ denoted $fir{r}_t(G)$ for brevity, as: $fir{r}_t(G)=\sum _{i=1}^{n-1}\sum _{j=i+1}^n|f_i-f_j|.$ The concept of an \emph{edge-joint} is also introduced to be the simple undirected graph obtained from two simple undirected graphs $G$ and $H$ by linking the edge $v{u}_{v\in V(G),u\in V(H)}$. This paper presents results for the undirected underlying graphs of Jaco Graphs, $J_n(x)$. Finally we pose an open problem with regards to $fir{r}_t^{\pm }(G).$

arXiv comment11 pages. Minor typographical errors corrected. An erroneous table replaced and standardized notation introduced