Periodic graph (graph theory)

In graph theory, a periodic graph typically refers to a graph that exhibits a certain kind of regularity or repetition in its structure. Although "periodic graph" is not a standard term with a universally accepted definition, it often relates to graphs that have a periodicity in their vertex arrangement or edge connections. For example, a periodic graph can be understood in the context of cellular structures or tessellations, where the graph is invariant under specific transformations, such as translations, rotations, or reflections.