@Article{JMS-56-206, author = {Huang , Danjun and Bao , Dan}, title = {Neighbor Sum Distinguishing Total Chromatic Number of Graphs with Lower Average Degree}, journal = {Journal of Mathematical Study}, year = {2023}, volume = {56}, number = {2}, pages = {206--218}, abstract = {

For a given simple graph $G = (V(G),E(G)),$ a proper total-$k$-coloring $c : V(G)∪E(G)→ \{1,2,...,k\}$ is neighbor sum distinguishing if $f(u) ≠ f(v)$ for each edge $uv ∈ E(G),$ where $f(v) = \sum_{wv∈E(G)} c(wv)+c(v).$ The smallest integer $k$ in such a coloring of $G$ is the neighbor sum distinguishing total chromatic number, denoted by $\chi^{''}_{\sum} (G).$ It has been conjectured that $\chi ^{''}_{\sum} (G) ≤ ∆(G)+3$ for any simple graph $G.$ Let $mad (G)=max\{ \frac{2|E(H)|}{ |V(H)|} :H⊆G\}$ be the maximum average degree of $G.$ In this paper, by using the famous Combinatorial Nullstellensatz, we prove $\chi^{''} _{\sum}(G) ≤ max\{9,∆(G)+2\}$ for any graph $G$ with $mad (G)<4.$ Furthermore, we characterize the neighbor sum distinguishing total chromatic number for every graph $G$ with $mad (G)<4$ and $∆(G)≥8.$

}, issn = {2617-8702}, doi = {https://doi.org/10.4208/jms.v56n2.23.06}, url = {http://global-sci.org/intro/article_detail/jms/21836.html} }