Higher order RG flow on the Wilson line in $$ \mathcal{N} $$ = 4 SYM

Extending earlier work, we find the two-loop term in the beta-function for the scalar coupling ζ in a generalized Wilson loop operator of the $$ \mathcal{N} $$ N = 4 SYM theory, working in the planar weak-coupling expansion. The beta-function for ζ has fixed points at ζ = ±1 and ζ = 0, corresponding respectively to the supersymmetric Wilson-Maldacena loop and to the standard Wilson loop without scalar coupling. As a consequence of our result for the beta-function, we obtain a prediction for the two-loop term in the anomalous dimension of the scalar field inserted on the standard Wilson loop. We also find a subset of higher-loop contributions (with highest powers of ζ at each order in ‘t Hooft coupling λ) coming from the scalar ladder graphs determining the corresponding terms in the five-loop beta-function. We discuss the related structure of the circular Wilson loop expectation value commenting, in particular, on consistency with a 1d defect version of the F-theorem. We also compute (to two loops in the planar ladder model approximation) the two-point correlators of scalars inserted on the Wilson line.

The (2,1)-total number of near-ladder graphs

A $(2,1)$-total labelling of a simple graph $G$ is a function $\pi \colon V(G)\cup E(G) \to \{0, \ldots, k\}$ such that: $\pi(u) \neq \pi(v)$ for $uv \in E(G)$; $\pi(uv) \neq \pi(vw)$ for $uv, vw \in E(G)$; and $|\pi(uv)-\pi(u)| \geq 2$ and $|\pi(uv)-\pi(v)| \geq 2$ for $uv \in E(G)$. The $(2,1)$-total number $\lambda_2^t(G)$ of $G$ is the least $k$ for which $G$ admits such a labelling. In 2008, Havet and Yu conjectured that $\lambda_2^t(G)\leq 5$ for every connected graph $G \not\cong K_4$ with $\Delta(G) \leq 3$. We prove that, for near-ladder graphs, $\lambda_2^t(G)=5$, verifying Havet and Yu's Conjecture for this class.

New Perspectives on Classical Meanness of Some Ladder Graphs

In this study, we investigate a new kind of mean labeling of graph. The ladder graph plays an important role in the area of communication networks, coding theory, and transportation engineering. Also, we found interesting new results corresponding to classical mean labeling for some ladder-related graphs and corona of ladder graphs with suitable examples.

On locating chromatic number of Möbius ladder graphs

In this paper, we are dealing with the study of locating chromatic number of Möbius-ladders. We prove that Möbius-ladders Mn with n even has locating chromatic number 4 if n≠6 and 6 if n=6.

Extending of Edge Even Graceful Labeling of Graphs to Strong r -Edge Even Graceful Labeling

Edge even graceful labeling of a graph G with p vertices and q edges is a bijective f from the set of edge E G to the set of positive integers 2,4 , … , 2 q such that all the vertex labels f ∗ V G , given by f ∗ u = ∑ u v ∈ E G f u v mod 2 k , where k = max p , q , are pairwise distinct. There are many graphs that do not have edge even graceful labeling, so in this paper, we have extended the definition of edge even graceful labeling to r -edge even graceful labeling and strong r -edge even graceful labeling. We have obtained the necessary conditions for more path-related graphs and cycle-related graphs to be an r -edge even graceful graph. Furthermore, the minimum number r for which the graphs: tortoise graph, double star graph, ladder and diagonal ladder graphs, helm graph, crown graph, sunflower graph, and sunflower planar graph, have an r -edge even graceful labeling was found. Finally, we proved that the even cycle C 2 n has a strong 2 -edge even graceful labeling when n is even.