diff -r ae5a542c958e -r fd5d1647f4f3 text/ncat.tex --- a/text/ncat.tex Fri May 07 11:18:39 2010 -0700 +++ b/text/ncat.tex Sun May 09 22:32:37 2010 -0700 @@ -1065,8 +1065,6 @@ \medskip -%\subsection{Tensor products} - We will use a simple special case of the above construction to define tensor products of modules. @@ -1084,9 +1082,6 @@ We will define a more general self tensor product (categorified coend) below. - - - %\nn{what about self tensor products /coends ?} \nn{maybe ``tensor product" is not the best name?} @@ -1095,6 +1090,68 @@ + +\subsection{Morphisms of $A_\infty$ 1-cat modules} + +In order to state and prove our version of the higher dimensional Deligne conjecture +(Section \ref{sec:deligne}), +we need to define morphisms of $A_\infty$ 1-cat modules and establish +some elementary properties of these. + +To motivate the definitions which follow, consider algebras $A$ and $B$, right/bi/left modules +$X_B$, $_BY_A$ and $Z_A$, and the familiar adjunction +\begin{eqnarray*} + \hom_A(X_B\ot {_BY_A} \to Z_A) &\cong& \hom_B(X_B \to \hom_A( {_BY_A} \to Z_A)) \\ + f &\mapsto& [x \mapsto f(x\ot -)] \\ + {}[x\ot y \mapsto g(x)(y)] & \leftarrowtail & g . +\end{eqnarray*} +\nn{how to do a left-pointing ``$\mapsto$"?} +If $A$ and $Z_A$ are both the ground field $\k$, this simplifies to +\[ + (X_B\ot {_BY})^* \cong \hom_B(X_B \to (_BY)^*) . +\] +We will establish the analogous isomorphism for a topological $A_\infty$ 1-cat $\cC$ +and modules $\cM_\cC$ and $_\cC\cN$, +\[ + (\cM_\cC\ot {_\cC\cN})^* \cong \hom_\cC(\cM_\cC \to (_\cC\cN)^*) . +\] + +We must now define the things appearing in the above equation. + +In the previous subsection we defined a tensor product of $A_\infty$ $n$-cat modules +for general $n$. +For $n=1$ this definition is a homotopy colimit indexed by subdivisions of a fixed interval $J$ +and their gluings (antirefinements). +(The tensor product will depend (functorially) on the choice of $J$.) +To a subdivision +\[ + J = I_1\cup \cdots\cup I_m +\] +we associate the chain complex +\[ + \cM(I_1)\ot\cC(I_2)\ot\cdots\ot\cC(I_{m-1})\ot\cN(I_m) . +\] +(If $D$ denotes the subdivision of $J$, then we denote this complex by $\psi(D)$.) +To each antirefinement we associate a chain map using the composition law of $\cC$ and the +module actions of $\cC$ on $\cM$ and $\cN$. +\def\olD{{\overline D}} +The underlying graded vector space of the homotopy colimit is +\[ + \bigoplus_l \bigoplus_{\olD} \psi(D_0)[l] , +\] +where $l$ runs through the natural numbers, $\olD = (D_0\to D_1\to\cdots\to D_l)$ +runs through chains of antirefinements, and $[l]$ denotes a grading shift. + +\nn{...} + + + + + + + + + \subsection{The $n{+}1$-category of sphere modules} \label{ssec:spherecat}