A topological grading on bordered Heegaard Floer homology

Abstract

In this paper, we construct a canonical grading on bordered Heegaard Floer homology by homotopy classes of nonvanishing vector fields. This grading is a generalization of our construction of an absolute grading on Heegaard Floer homology and it extends the well-known grading with values in a noncommutative group defined by Lipshitz-Ozsváth-Thurston.

35 pages, 20 figures, improvements in the presentation, to appear in Quantum Topology