Communications in Analysis and Geometry
Volume 19 (2011)
Semi-perfect obstruction theory and Donaldson–Thomas invariants of derived objects
Pages: 807 – 830
We introduce a semi-perfect obstruction theory of a Deligne–Mumford stack $X$ that consists of localperfect obstruction theories with a global obstruction sheaf. We construct the virtual cycle of aDeligne–Mumford stack with a semi-perfect obstruction theory. We use semi-perfect obstruction theoryto construct virtual cycles of moduli of derived objects on Calabi–Yau threefolds.