Problems
Everything in the archive: the problem as it was posed, what has been attempted against it, and who checked each attempt. The mark down the left of the list says who has looked — a person, a machine, or nobody yet. Human reviews and machine checks are counted separately and are never added together.
2 problems
showing 1–2
Must every graph with n vertices and δ n^2 edges contain large subgraphs in which every two edges lie on specified short cycles? A dense high-girth construction refutes the statement when δ may shrink with n.
For every connected graph, is the deviation of its adjacency eigenvalues at most its order divided by its average distance? Exact lollipop-graph certificates refute the inequality when deviation means population standard deviation, under…