Given a link in the three-sphere, Z. Szab\'o and the second author
constructed a spectral sequence starting at the Khovanov homology of the link
and converging to the Heegaard Floer homology of its branched double-cover. The
aim of this paper and its sequel is to explicitly calculate this spectral
sequence, using bordered Floer homology. There are two primary ingredients in
this computation: an explicit calculation of filtered bimodules associated to
Dehn twists and a pairing theorem for polygons.
In this paper we prove another pairing theorem for bordered Floer homology.
Unlike the original pairing theorem, this one is stated in terms of
homomorphisms, not tensor products. The present formulation is closer in spirit
to the usual TQFT framework, and allows a more direct comparison with
Fukaya-categorical constructions. The result also leads to various dualities in
bordered Floer homology.
Bordered Heegaard Floer homology is a three-manifold invariant which
associates to a surface F an algebra A(F) and to a three-manifold Y with
boundary identified with F a module over A(F). In this paper, we establish
naturality properties of this invariant. Changing the diffeomorphism between F
and the boundary of Y tensors the bordered invariant with a suitable bimodule
over A(F). These bimodules give an action of a suitably based mapping class
group on the category of modules over A(F).
We construct Heegaard Floer theory for 3-manifolds with connected boundary.
The theory associates to an oriented two-manifold a differential graded
algebra. For a three-manifold with specified boundary, the invariant comes in
two different versions, one of which (type D) is a module over the algebra and
the other of which (type A) is an A-infinity module. Both are well-defined up
to chain homotopy equivalence.