arXiv subjects

P. K. Ashraf

Publications and source records attributed to P. K. Ashraf.

2 recordsLinked to original sources

arXiv2016

A Study on Set-Valuations of Signed Graphs

Let $X$ be a non-empty ground set and $\mathcal{P}(X)$ be its power set. A set-labeling (or a set-valuation) of a graph $G$ is an injective set-valued function $f:V(G)\to \mathcal{P}(X)$ such that the induced function $f^\oplus:E(G) \to \mathcal{P}(X)$ is defined by $f^\oplus(uv) = f(u)\oplus f(v)$, where $f(u)\oplus f(v)$ is the symmetric difference of the sets $f(u)$ and $f(v)$. A graph which admits a set-labeling is known to be a set-labeled graph. A set-labeling $f$ of a graph $G$ is said to be a set-indexer of $G$ if the associated function $f^\oplus$ is also injective. In this paper, we define the notion of set-valuations of signed graphs and discuss certain properties of signed graphs which admits certain types of set-valuations.

math.GM↗

arXiv2016

Some New Results on Integer Additive Set-Valued Signed Graphs

Let $X$ denotes a set of non-negative integers and $\mathscr{P}(X)$ be its power set. An integer additive set-labeling (IASL) of a graph $G$ is an injective set-valued function $f:V(G)\to \mathscr{P}(X)-\{\emptyset\}$ such that the induced function $f^+:E(G) \to \mathscr{P}(X)-\{\emptyset\}$ is defined by $f^+(uv)=f(u)+f(v);\ \forall\, uv\in E(G)$, where $f(u)+f(v)$ is the sumset of $f(u)$ and $f(v)$. An IASL of a signed graph is an IASL of its underlying graph $G$ together with the signature $σ$ defined by $σ(uv)=(-1)^{|f^+(uv)|};\ \forall\, uv\in E(Σ)$. In this paper, we discuss certain characteristics of the signed graphs which admits certain types of integer additive set-labelings.

math.GM↗