Antipode

Given a point , the point  which is the antipodal point of  is said to be the antipode of .

The term antipode is also used in plane geometry. Given a central conic (or circle) and a point  lying on it, draw a line passing through  and the center  of the conic. Then the antipode  of  is other point lying on the conic through which the line  passes.

The antipode of a vertex  in a graph is a vertex  at greatest possible distance from . An antipodal graph is then defined as a connected graph in which each vertex has exactly one antipode (Gorovoy and Zmiaikou 2021).

REFERENCES

Gorovoy, D. and Zmiaikou, D. "On Graphs with Unique Geoodesics and Antipodes." 19 Nov 2021. https://arxiv.org/abs/2111.09987.

Tietze, H. Famous Problems of Mathematics: Solved and Unsolved Mathematics Problems from Antiquity to Modern Times. New York: Graylock Press, p. 25, 1965.