^{1}Department of Mathematics, Sri Paramakalyani College, Alwarkurichi{627 412, India

^{2}Department of Mathematics, Thiruvalluvar College,, Papanasam{627 425, India

^{3}Department of Mathematics, Manonmaniam Sundaranar University, Tirunelveli{ 627 012, India.

Abstract

In this paper we introduce remainder cordial labeling of graphs. Let $G$ be a $(p,q)$ graph. Let $f:V(G)\rightarrow \{1,2,...,p\}$ be a $1-1$ map. For each edge $uv$ assign the label $r$ where $r$ is the remainder when $f(u)$ is divided by $f(v)$ or $f(v)$ is divided by $f(u)$ according as $f(u)\geq f(v)$ or $f(v)\geq f(u)$. The function$f$ is called a remainder cordial labeling of $G$ if $\left| e_{f}(0) - e_f(1) \right|\leq 1$ where $e_{f}(0)$ and $e_{f}(1)$ respectively denote the number of edges labelled with even integers and odd integers. A graph $G$ with a remainder cordial labeling is called a remainder cordial graph. We investigate the remainder cordial behavior of path, cycle, star, bistar, crown, comb, wheel, complete bipartite $K_{2,n}$ graph. Finally we propose a conjecture on complete graph $K_{n}$.