Bounds on the size of super edge-magic graphs depending on the girth

Let G = (V,E) be a graph of order p and size q. It is known that if G is super edge-magic graph then q 2p−3. Furthermore, if G is super edge-magic and q = 2p−3, then the girth of G is 3. It is also known that if the girth of G is at least 4 and G is super edge-magic then q 2p − 5. In this paper we show that there are infinitely many graphs which are super edge-magic, have girth 5, and q = 2p−5. Therefore the maximum size for super edge-magic graphs of girth 5 cannot be reduced with respect to the maximum size of super edge-magic graphs of girth 4.Preprin

Some results concerning the valences of (super) edge-magic graphs

A graph $G$ is called edge-magic if there exists a bijective function $f:V\left(G\right) \cup E\left(G\right)\rightarrow \left\{1, 2, \ldots , \left\vert V\left( G\right) \right\vert +\left\vert E\left( G\right) \right\vert \right\}$ such that $f\left(u\right) + f\left(v\right) + f\left(uv\right)$ is a constant (called the valence of $f$) for each $uv\in E\left( G\right)$. If $f\left(V \left(G\right)\right) =\left\{1, 2, \ldots , \left\vert V\left( G\right) \right\vert \right\}$, then $G$ is called a super edge-magic graph. A stronger version of edge-magic and super edge-magic graphs appeared when the concepts of perfect edge-magic and perfect super edge-magic graphs were introduced. The super edge-magic deficiency $\mu_{s}\left(G\right)$ of a graph $G$ is defined to be either the smallest nonnegative integer $n$ with the property that $G \cup nK_{1}$ is super edge-magic or $+ \infty$ if there exists no such integer $n$. On the other hand, the edge-magic deficiency $\mu\left(G\right)$ of a graph $G$ is the smallest nonnegative integer $n$ for which $G\cup nK_{1}$ is edge-magic, being $\mu\left(G\right)$ always finite. In this paper, the concepts of (super) edge-magic deficiency are generalized using the concepts of perfect (super) edge-magic graphs. This naturally leads to the study of the valences of edge-magic and super edge-magic labelings. We present some general results in this direction and study the perfect (super) edge-magic deficiency of the star $K_{1,n}$

Problemas abiertos sobre etiquetamientos super edge-magic y temas relacionados

El tema de los etiquetamientos de grafos ha experimentado un fuerte impulso en los últimos 40 años, muestra de ello son los dos libros dedicados en exclusiva a ellos, un completísimo artículo ”survey” y más de 1000 artículos en la literatura. En este artículo exploramos algunas preguntas abiertas sobre etiquetamientos super edge-magic. Nos interesa particularmente este tipo de etiquetamientos, debido a la cantidad de relaciones que poseen con otras clases de etiquetamientos, principalmente los graciosos y los armónicos.Preprin

Bounds on the size of super edge-magic graphs depending on the girth

Let G = (V,E) be a graph of order p and size q. It is known that if G is super edge-magic graph then q 2p−3. Furthermore, if G is super edge-magic and q = 2p−3, then the girth of G is 3. It is also known that if the girth of G is at least 4 and G is super edge-magic then q 2p − 5. In this paper we show that there are infinitely many graphs which are super edge-magic, have girth 5, and q = 2p−5. Therefore the maximum size for super edge-magic graphs of girth 5 cannot be reduced with respect to the maximum size of super edge-magic graphs of girth 4

Bounds on the size of super edge-magic graphs depending on the girth

Let G = (V,E) be a graph of order p and size q. It is known that if G is super edge-magic graph then q 2p−3. Furthermore, if G is super edge-magic and q = 2p−3, then the girth of G is 3. It is also known that if the girth of G is at least 4 and G is super edge-magic then q 2p − 5. In this paper we show that there are infinitely many graphs which are super edge-magic, have girth 5, and q = 2p−5. Therefore the maximum size for super edge-magic graphs of girth 5 cannot be reduced with respect to the maximum size of super edge-magic graphs of girth 4