I will introduce an orientifold version of Donaldson–Thomas theory, which is a theory of enumerative invariants counting orthosymplectic objects, and is related to orientifold string theory. Examples include DT invariants counting orthosymplectic sheaves on a Calabi–Yau threefold with a Bridgeland stability condition, and DT invariants counting orthosymplectic quiver representations. I will also discuss wall-crossing for these DT invariants, which relates the invariants for different stability conditions.
Note: there will be a lunch break at around noon, and the talk and/or discussions will continue over lunch in the lecture hall.