diff -r 77b0cdeb0fcd -r 217b6a870532 text/ncat.tex --- a/text/ncat.tex Thu Mar 18 19:40:46 2010 +0000 +++ b/text/ncat.tex Sat Mar 27 03:07:45 2010 +0000 @@ -156,18 +156,17 @@ \begin{figure}[!ht] $$ -\begin{tikzpicture}[every label/.style={green}] -\node[fill=black, circle, label=below:$E$](S) at (0,0) {}; -\node[fill=black, circle, label=above:$E$](N) at (0,2) {}; +\begin{tikzpicture}[%every label/.style={green} + ] +\node[fill=black, circle, label=below:$E$, inner sep=2pt](S) at (0,0) {}; +\node[fill=black, circle, label=above:$E$, inner sep=2pt](N) at (0,2) {}; \draw (S) arc (-90:90:1); \draw (N) arc (90:270:1); \node[left] at (-1,1) {$B_1$}; \node[right] at (1,1) {$B_2$}; \end{tikzpicture} $$ -$$\mathfig{.4}{tempkw/blah3}$$ -\caption{Combining two balls to get a full boundary -\nn{maybe smaller dots for $E$ in pdf fig}}\label{blah3}\end{figure} +\caption{Combining two balls to get a full boundary.}\label{blah3}\end{figure} Note that we insist on injectivity above. @@ -215,8 +214,21 @@ \end{axiom} \begin{figure}[!ht] +$$ +\begin{tikzpicture}[%every label/.style={green}, + x=1.5cm,y=1.5cm] +\node[fill=black, circle, label=below:$E$, inner sep=2pt](S) at (0,0) {}; +\node[fill=black, circle, label=above:$E$, inner sep=2pt](N) at (0,2) {}; +\draw (S) arc (-90:90:1); +\draw (N) arc (90:270:1); +\draw (N) -- (S); +\node[left] at (-1/4,1) {$B_1$}; +\node[right] at (1/4,1) {$B_2$}; +\node at (1/6,3/2) {$Y$}; +\end{tikzpicture} +$$ $$\mathfig{.4}{tempkw/blah5}$$ -\caption{From two balls to one ball}\label{blah5}\end{figure} +\caption{From two balls to one ball.}\label{blah5}\end{figure} \begin{axiom}[Strict associativity] \label{nca-assoc} The composition (gluing) maps above are strictly associative. @@ -224,7 +236,7 @@ \begin{figure}[!ht] $$\mathfig{.65}{tempkw/blah6}$$ -\caption{An example of strict associativity}\label{blah6}\end{figure} +\caption{An example of strict associativity.}\label{blah6}\end{figure} \nn{figure \ref{blah6} (blah6) needs a dotted line in the south split ball} @@ -263,7 +275,7 @@ \begin{figure}[!ht] $$\mathfig{.8}{tempkw/blah7}$$ -\caption{Operadish composition and associativity}\label{blah7}\end{figure} +\caption{Operad composition and associativity}\label{blah7}\end{figure} The next axiom is related to identity morphisms, though that might not be immediately obvious. @@ -520,8 +532,7 @@ \label{ex:traditional-n-categories} Given a `traditional $n$-category with strong duality' $C$ define $\cC(X)$, for $X$ a $k$-ball or $k$-sphere with $k < n$, -to be the set of all $C$-labeled sub cell complexes of $X$. -(See Subsection \ref{sec:fields}.) +to be the set of all $C$-labeled sub cell complexes of $X$ (c.f. \S \ref{sec:fields}). For $X$ an $n$-ball and $c\in \cC(\bd X)$, define $\cC(X)$ to finite linear combinations of $C$-labeled sub cell complexes of $X$ modulo the kernel of the evaluation map. @@ -628,7 +639,7 @@ \begin{figure}[!ht] \begin{equation*} -\mathfig{.63}{tempkw/zz2} +\mathfig{.63}{ncat/zz2} \end{equation*} \caption{A small part of $\cJ(W)$} \label{partofJfig} @@ -733,8 +744,7 @@ \subsection{Modules} -Next we define [$A_\infty$] $n$-category modules (a.k.a.\ representations, -a.k.a.\ actions). +Next we define topological and $A_\infty$ $n$-category modules. The definition will be very similar to that of $n$-categories, but with $k$-balls replaced by {\it marked $k$-balls,} defined below. \nn{** need to make sure all revisions of $n$-cat def are also made to module def.} @@ -745,10 +755,10 @@ Such a $W$ gives rise to a module for the $n$-category associated to $\bd W$. This will be explained in more detail as we present the axioms. -Fix an $n$-category $\cC$. +Throughout, we fix an $n$-category $\cC$. For all but one axiom, it doesn't matter whether $\cC$ is a topological $n$-category or an $A_\infty$ $n$-category. We state the final axiom, on actions of homeomorphisms, differently in the two cases. Define a {\it marked $k$-ball} to be a pair $(B, N)$ homeomorphic to the pair -(standard $k$-ball, northern hemisphere in boundary of standard $k$-ball). +$$(\text{standard $k$-ball}, \text{northern hemisphere in boundary of standard $k$-ball}).$$ We call $B$ the ball and $N$ the marking. A homeomorphism between marked $k$-balls is a homeomorphism of balls which restricts to a homeomorphism of markings. @@ -831,16 +841,16 @@ \begin{figure}[!ht] \begin{equation*} -\mathfig{.63}{tempkw/zz3} +\mathfig{.4}{ncat/zz3} \end{equation*} -\caption{Module composition (top); $n$-category action (bottom)} +\caption{Module composition (top); $n$-category action (bottom).} \label{zzz3} \end{figure} First, we can compose two module morphisms to get another module morphism. \mmpar{Module axiom 6}{Module composition} -{Let $M = M_1 \cup_Y M_2$, where $M$, $M_1$ and $M_2$ are marked $k$-balls ($0\le k\le n$) +{Let $M = M_1 \cup_Y M_2$, where $M$, $M_1$ and $M_2$ are marked $k$-balls (with $0\le k\le n$) and $Y = M_1\cap M_2$ is a marked $k{-}1$-ball. Let $E = \bd Y$, which is a marked $k{-}2$-hemisphere. Note that each of $M$, $M_1$ and $M_2$ has its boundary split into two marked $k{-}1$-balls by $E$. @@ -886,7 +896,7 @@ \begin{figure}[!ht] \begin{equation*} -\mathfig{1}{tempkw/zz1b} +\mathfig{0.49}{ncat/zz0} \mathfig{0.49}{ncat/zz1} \end{equation*} \caption{Two examples of mixed associativity} \label{zzz1b} @@ -1015,9 +1025,9 @@ with $M_{ib}\cap Y_i$ being the marking. (See Figure \ref{mblabel}.) \begin{figure}[!ht]\begin{equation*} -\mathfig{.9}{tempkw/mblabel} +\mathfig{.6}{ncat/mblabel} \end{equation*}\caption{A permissible decomposition of a manifold -whose boundary components are labeled by $\cC$ modules $\{\cN_i\}$.}\label{mblabel}\end{figure} +whose boundary components are labeled by $\cC$ modules $\{\cN_i\}$. Marked balls are shown shaded, plain balls are unshaded.}\label{mblabel}\end{figure} Given permissible decompositions $x$ and $y$, we say that $x$ is a refinement of $y$, or write $x \le y$, if each ball of $y$ is a union of balls of $x$. This defines a partial ordering $\cJ(W)$, which we will think of as a category. @@ -1087,9 +1097,8 @@ In this subsection we define an $n{+}1$-category $\cS$ of ``sphere modules" whose objects correspond to $n$-categories. This is a version of the familiar algebras-bimodules-intertwiners 2-category. -(Terminology: It is clearly appropriate to call an $S^0$ modules a bimodule, -since a 0-sphere has an obvious bi-ness. -This is much less true for higher dimensional spheres, +(Terminology: It is clearly appropriate to call an $S^0$ module a bimodule, +but this is much less true for higher dimensional spheres, so we prefer the term ``sphere module" for the general case.) The $0$- through $n$-dimensional parts of $\cC$ are various sorts of modules, and we describe @@ -1146,7 +1155,7 @@ \medskip -Part of the structure of an $n$-cat 0-sphere module is captured my saying it is +Part of the structure of an $n$-category 0-sphere module is captured by saying it is a collection $\cD^{ab}$ of $n{-}1$-categories, indexed by pairs $(a, b)$ of objects (0-morphisms) of $\cA$ and $\cB$. Let $J$ be some standard 0-marked 1-ball (i.e.\ an interval with a marked point in its interior).