An absolute Z/2 grading on bordered Heegaard Floer homology.

Bordered Heegaard Floer homology is an invariant for 3-manifolds, which associates to a surface Fan algebra A(Z), and to a 3-manifold Y with boundary, together with an orientation-preserving diffeomorphism ø : F → ∂Y, a module over A(Z). In [10] we defined relative Z/2 differential gradings on the algebra A(Z) and the modules over it. In this paper, we turn the relative grading into an absolute one, and show that the resulting Z/2-graded module is an invariant of the bordered 3-manifold. [ABSTRACT FROM AUTHOR]