  Let M be a closed oriented 3-manifold with first Betti number one. Its
equivariant linking pairing may be seen as a two-dimensional cohomology class
in an appropriate infinite cyclic covering of the configuration space of
ordered pairs of distinct points of M. We show how to define the equivariant
cube Q(M,K) of this Blanchfield pairing with respect to a framed knot K that
generates H_1(M;Z)/Torsion. We present the invariant Q(M,K) and some of its
properties including a surgery formula. Via surgery, the invariant Q is
equivalent to an invariant Q' of null-homologous knots in rational homology
spheres, that is conjecturally equivalent to the two-loop part of the
Kontsevich integral. We generalize the construction of Q' to obtain a
topological construction for an invariant that is conjecturally equivalent to
the whole Kricker rational lift of the Kontsevich integral for null-homologous
knots in rational homology spheres.
