diff -r 0df8bde1c896 -r 638be64bd329 text/a_inf_blob.tex --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/text/a_inf_blob.tex Mon Aug 17 22:51:08 2009 +0000 @@ -0,0 +1,60 @@ +%!TEX root = ../blob1.tex + +\section{The blob complex for $A_\infty$ $n$-categories} +\label{sec:ainfblob} + +Given an $A_\infty$ $n$-category $\cC$ and an $n$-manifold $M$, we define the blob +complex $\bc_*(M)$ to the be the colimit $\cC(M)$ of Section \ref{sec:ncats}. +\nn{say something about this being anticlimatically tautological?} +We will show below +\nn{give ref} +that this agrees (up to homotopy) with our original definition of the blob complex +in the case of plain $n$-categories. +When we need to distinguish between the new and old definitions, we will refer to the +new-fangled and old-fashioned blob complex. + +\medskip + +Let $M^n = Y^k\times F^{n-k}$. +Let $C$ be a plain $n$-category. +Let $\cF$ be the $A_\infty$ $k$-category which assigns to a $k$-ball +$X$ the old-fashioned blob complex $\bc_*(X\times F)$. + +\begin{thm} +The old-fashioned blob complex $\bc_*^C(Y\times F)$ is homotopy equivalent to the +new-fangled blob complex $\bc_*^\cF(Y)$. +\end{thm} + +\begin{proof} +We will use the concrete description of the colimit from Subsection \ref{ss:ncat_fields}. + +First we define a map from $\bc_*^\cF(Y)$ to $\bc_*^C(Y\times F)$. +In filtration degree 0 we just glue together the various blob diagrams on $X\times F$ +(where $X$ is a component of a permissible decomposition of $Y$) to get a blob diagram on +$Y\times F$. +In filtration degrees 1 and higher we define the map to be zero. +It is easy to check that this is a chain map. + +Next we define a map from $\bc_*^C(Y\times F)$ to $\bc_*^\cF(Y)$. +Actually, we will define it on the homotopy equivalent subcomplex +$\cS_* \sub \bc_*^C(Y\times F)$ generated by blob diagrams which are small with respect to some open cover +of $Y\times F$. +\nn{need reference to small blob lemma} +We will have to show eventually that this is independent (up to homotopy) of the choice of cover. +Also, for a fixed choice of cover we will only be able to define the map for blob degree less than +some bound, but this bound goes to infinity as the cover become finer. + +\nn{....} +\end{proof} + +\nn{need to say something about dim $< n$ above} + + + +\medskip +\hrule +\medskip + +\nn{to be continued...} +\medskip +