Core Concepts
The 2-domination number of cylindrical graphs, which are the Cartesian products of a path and a cycle, can be efficiently computed using lower and upper bounds, especially for cycles with order n ≡ 0 (mod 3) and arbitrary paths.
Abstract
The authors present both lower and upper bounds for the 2-domination number of cylindrical graphs, which allows them to compute the exact value of this parameter in certain cases.
Key highlights:
- The 2-domination number is the minimum cardinal of a 2-dominating set, where each vertex not in the set has at least two neighbors in it.
- The authors adapt the technique of "wasted domination" to compute a lower bound for the 2-domination number of cylindrical graphs.
- They use the tropical matrix product to obtain the desired lower bound.
- For cycles with order n ≡ 0 (mod 3) and arbitrary paths, the authors provide a regular patterned construction of a minimum 2-dominating set, which allows them to compute the exact 2-domination number.
- The proofs involve technical lemmas and the use of a computer to perform the necessary computations.