English

On local antimagic total labeling of amalgamation graphs

Combinatorics 2022-03-15 v1

Abstract

Let G=(V,E)G = (V,E) be a connected simple graph of order pp and size qq. A graph GG is called local antimagic (total) if GG admits a local antimagic (total) labeling. A bijection g:E{1,2,,q}g : E \to \{1,2,\ldots,q\} is called a local antimagic labeling of GG if for any two adjacent vertices uu and vv, we have g+(u)g+(v)g^+(u) \ne g^+(v), where g+(u)=eE(u)g(e)g^+(u) = \sum_{e\in E(u)} g(e), and E(u)E(u) is the set of edges incident to uu. Similarly, a bijection f:V(G)E(G){1,2,,p+q}f:V(G)\cup E(G)\to \{1,2,\ldots,p+q\} is called a local antimagic total labeling of GG if for any two adjacent vertices uu and vv, we have wf(u)wf(v)w_f(u)\ne w_f(v), where wf(u)=f(u)+eE(u)f(e)w_f(u) = f(u) + \sum_{e\in E(u)} f(e). Thus, any local antimagic (total) labeling induces a proper vertex coloring of GG if vertex vv is assigned the color g+(v)g^+(v) (respectively, wf(u)w_f(u)). The local antimagic (total) chromatic number, denoted χla(G)\chi_{la}(G) (respectively χlat(G)\chi_{lat}(G)), is the minimum number of induced colors taken over local antimagic (total) labeling of GG. In this paper, we determined χlat(G)\chi_{lat}(G) where GG is the amalgamation of complete graphs.

Keywords

Cite

@article{arxiv.2203.06337,
  title  = {On local antimagic total labeling of amalgamation graphs},
  author = {Gee-Choon Lau and Wai-Chee Shiu},
  journal= {arXiv preprint arXiv:2203.06337},
  year   = {2022}
}