equivariant motivic Hall algebras, and endow them with natural integration maps to the ring
of dual numbers. The construction allows a systematic treatment of reduced Donaldson–
Thomas (DT) invariants by Hall algebra techniques. We calculate reduced DT invariants for
K 3× E and abelian threefolds for several imprimitive curve classes. This verifies (in special
cases) multiple cover formulas conjectured by Oberdieck–Pandharipande and Bryan …