Oct 4, 2025
Strongly Regular
Mathober Day 4: Strongly
Spent some time trying to understand strongly regular today. Each vertex has the same number of adjacent vertices, each pair of adjacent vertices has the same number of neighbors in common, and every non-adjacent pair have the same number of neighbors in common. And they are characterized by these up to isomorphism. The Paley graph is (13, 6, 2, 3). If a graph is strongly regular, so is its complement, so that's the purple one here, (13, 6, 2, 3). I think.