A ribbon obstruction and derivatives of knots

We define an obstruction for a knot to be ?[?]-homology ribbon, and use this provide restrictions on the integers that can occur as triple linking numbers of derivative links knots are either homotopy ribbon or doubly slice. Our main application finds new non-doubly slice knots. In particular, gives information solvable filtration Taehee Kim: algebraically need not (1)-solvable, (0.5, 1)-solvable. introduce notion (1)-solvable find is (0.5)-solvable but (1)-solvable. also discuss potential connections unsolved conjectures in concordance, such generalised versions Kauffman’s conjecture. Moreover, it possible our could fail vanish knot.