A result on $K$-(2,1)-Total choosability of planar graphs
Received:March 14, 2021  Revised:November 24, 2021
Key Word: $L$-(2,1)-total labeling   $k$-(2,1)-total choosable   planar graphs
Fund ProjectL:
 Author Name Affiliation Address Lei SUN Shandong Normal University No.1,University Road,Science Park,Changqing District,Ji''nan Yan SONG Shandong Normal University No.1,University Road,Science Park,Changqing District,Ji''nan
Hits: 14
A list assignment of a graph $G$ is a function $L:V(G)\cup E(G)\rightarrow 2^{N}$. A graph $G$ is $L$-(2,1)-Total labeling if there exists a function $c$ such that $c(x)\in L(x)$ for all $x\in V(G)\cup E(G)$, $|c(u)-c(v)|\geq 1$ if $uv\in E(G)$, $|c(e_{1})-c(e_{2})|\geq 1$ if the edges $e_{1}$ and $e_{2}$ are adjacent, and $|c(u)-c(e)|\geq 2$ if the vertex $u$ is incident to the edge $e$.A graph $G$ is $k$-(2,1)-Total choosable if G is $L$-(2,1)-Total labeling for every list assignment $L$ provided that $|L(x)|=k,x\in V(G)\cup E(G)$. The $(2,1)$-Total choice number of $G$, denoted by $C_{(2,1)}^{T}$, is the minimum $k$ such that $G$ is $k$-(2,1)-Total choosable. In this paper, we prove that if $G$ is a planar graph with $\Delta(G)\geq 11$, then $C_{(2,1)}^{T}(G)\leq\Delta+4$.