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
Do the tree-level amplitudes A_n(1^-, 2^+, …, n^+) vanish identically, or can they be nonzero in half-collinear kinematics - and if nonzero, what is their all-n closed form?
Do n point charges whose electrostatic potential has only non-degenerate critical points always have at most (n-1)^2 of them? A configuration of five charges - three at the vertices of an equilateral triangle plus two small central charges…