# HG changeset patch # User Kevin Walker # Date 1323366316 28800 # Node ID 6cfc2dc6ec6edc56ecc36d7f1125e1b5a660f378 # Parent d73a88d7849860fb432836bfac666eb714bce897 beginning final read-through; minor changes to intro diff -r d73a88d78498 -r 6cfc2dc6ec6e text/intro.tex --- a/text/intro.tex Wed Dec 07 23:00:54 2011 -0800 +++ b/text/intro.tex Thu Dec 08 09:45:16 2011 -0800 @@ -177,7 +177,7 @@ For non-semi-simple TQFTs, this approach is less satisfactory. Our main motivating example (though we will not develop it in this paper) -is the (decapitated) $4{+}1$-dimensional TQFT associated to Khovanov homology. +is the $(4{+}\varepsilon)$-dimensional TQFT associated to Khovanov homology. It associates a bigraded vector space $A_{Kh}(W^4, L)$ to a 4-manifold $W$ together with a link $L \subset \bd W$. The original Khovanov homology of a link in $S^3$ is recovered as $A_{Kh}(B^4, L)$. @@ -209,10 +209,10 @@ Instead, we would prefer a definition for a derived version of $A_{Kh}(W^4, L)$ which is manifestly invariant. -(That is, a definition that does not +In other words, we want a definition that does not involve choosing a decomposition of $W$. After all, one of the virtues of our starting point --- TQFTs via field and local relations --- -is that it has just this sort of manifest invariance.) +is that it has just this sort of manifest invariance. The solution is to replace $A_{Kh}(W^4, L)$, which is a quotient \[ @@ -225,7 +225,8 @@ Here $\bc_0$ is linear combinations of fields on $W$, $\bc_1$ is linear combinations of local relations on $W$, $\bc_2$ is linear combinations of relations amongst relations on $W$, -and so on. We now have a short exact sequence of chain complexes relating resolutions of the link $L$ +and so on. +We now have a long exact sequence of chain complexes relating resolutions of the link $L$ (c.f. Lemma \ref{lem:hochschild-exact} which shows exactness with respect to boundary conditions in the context of Hochschild homology). @@ -425,7 +426,7 @@ (see \S \ref{ss:product-formula}). Fix a disk-like $n$-category $\cC$, which we'll omit from the notation. -Recall that for any $(n-1)$-manifold $Y$, the blob complex $\bc_*(Y)$ is naturally an $A_\infty$ 1-category. +Recall that for any $(n{-}1)$-manifold $Y$, the blob complex $\bc_*(Y)$ is naturally an $A_\infty$ 1-category. (See Appendix \ref{sec:comparing-A-infty} for the translation between disk-like $A_\infty$ $1$-categories and the usual algebraic notion of an $A_\infty$ category.)