# Journal of the Ramanujan Mathematical Society

Volume 36, Issue 4, December 2021 pp. 267–273.

Center of Cartesian and strong product of digraphs

**Authors**:
Prasanth G. Narasimha-Shenoi and Mary Shalet Thottungal Joseph

**Author institution:**Department of Mathematics, Government College Chittur, Palakkad, Kerala 678 104, India

**Summary: **
Let D=(V,E) be a digraph and u, v ∈ V(D). The metric
maximum distance is defined by
md(u,v) = max {{d}(u,v), {d}(v,u)}
where {d}(u,v) denote the length of a shortest
directed u-v path in D. The eccentricity of a vertex v
in D is defined by ecc(v) = max {md(v,u): u ∈
V(D)}. The center C(D) of a strongly connected digraph
consist of all the vertices with minimum eccentricity. The
relationship between the center of the Cartesian and strong
product of two or more digraphs and its factor graphs have been
studied in this article.

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