diff -r ec3af8dfcb3c -r a3311a926113 text/ncat.tex --- a/text/ncat.tex Tue Jul 21 16:21:20 2009 +0000 +++ b/text/ncat.tex Tue Jul 21 18:45:18 2009 +0000 @@ -253,7 +253,23 @@ Taking singular chains converts a space-type $A_\infty$ $n$-category into a chain complex type $A_\infty$ $n$-category. +\medskip +The alert reader will have already noticed that our definition of (plain) $n$-category +is extremely similar to our definition of topological fields. +The only difference is that for the $n$-category definition we restrict our attention to balls +(and their boundaries), while for fields we consider all manifolds. +\nn{also: difference at the top dimension; fix this} +Thus a system of fields determines an $n$-category simply by restricting our attention to +balls. +The $n$-category can be thought of as the local part of the fields. +Conversely, given an $n$-category we can construct a system of fields via +\nn{gluing, or a universal construction} + +\nn{Next, say something about $A_\infty$ $n$-categories and ``homological" systems +of fields. +The universal (colimit) construction becomes our generalized definition of blob homology. +Need to explain how it relates to the old definition.} \medskip @@ -275,9 +291,10 @@ \item traditional $n$-cat defs (e.g. *-1-cat, pivotal 2-cat) imply our def of plain $n$-cat \item conversely, our def implies other defs \item traditional $A_\infty$ 1-cat def implies our def -\item ... and vice-versa +\item ... and vice-versa (already done in appendix) \item say something about unoriented vs oriented vs spin vs pin for $n=1$ (and $n=2$?) \item spell out what difference (if any) Top vs PL vs Smooth makes +\item explain relation between old-fashioned blob homology and new-fangled blob homology \end{itemize}