# HG changeset patch # User kevin@6e1638ff-ae45-0410-89bd-df963105f760 # Date 1267820828 0 # Node ID 1acb5f508cf6cdfed40dd7e9a8a15b66b94955c2 # Parent d13df7f3b2de1ce0bb97976cb0c61d6420f7baa5 ... diff -r d13df7f3b2de -r 1acb5f508cf6 text/hochschild.tex --- a/text/hochschild.tex Wed Mar 03 20:17:52 2010 +0000 +++ b/text/hochschild.tex Fri Mar 05 20:27:08 2010 +0000 @@ -38,26 +38,33 @@ We want to show that $\bc_*(S^1)$ is homotopy equivalent to the Hochschild complex of $C$. -Note that both complexes are free (and hence projective), so it suffices to show that they -are quasi-isomorphic. In order to prove this we will need to extend the definition of the blob complex to allow points to also be labeled by elements of $C$-$C$-bimodules. +(See Subsections \ref{moddecss} and \ref{ssec:spherecat} for a more general (i.e.\ $n>1$) +version of this construction.) Fix points $p_1, \ldots, p_k \in S^1$ and $C$-$C$-bimodules $M_1, \ldots M_k$. We define a blob-like complex $K_*(S^1, (p_i), (M_i))$. -The fields have elements of $M_i$ labeling $p_i$ and elements of $C$ labeling -other points. +The fields have elements of $M_i$ labeling +the fixed points $p_i$ and elements of $C$ labeling other (variable) points. +As before, the regions between the marked points are labeled by +objects of $\cC$. The blob twig labels lie in kernels of evaluation maps. -(The range of these evaluation maps is a tensor product (over $C$) of $M_i$'s.) +(The range of these evaluation maps is a tensor product (over $C$) of $M_i$'s, +corresponding to the $p_i$'s that lie within the twig blob.) Let $K_*(M) = K_*(S^1, (*), (M))$, where $* \in S^1$ is some standard base point. In other words, fields for $K_*(M)$ have an element of $M$ at the fixed point $*$ and elements of $C$ at variable other points. +In the theorems, propositions and lemmas below we make various claims +about complexes being homotopy equivalent. +In all cases the complexes in question are free (and hence projective), +so it suffices to show that they are quasi-isomorphic. We claim that \begin{thm} \label{hochthm} -The blob complex $\bc_*(S^1; C)$ on the circle is quasi-isomorphic to the +The blob complex $\bc_*(S^1; C)$ on the circle is homotopy equivalent to the usual Hochschild complex for $C$. \end{thm} @@ -71,7 +78,7 @@ Next, we show that for any $C$-$C$-bimodule $M$, \begin{prop} \label{prop:hoch} -The complex $K_*(M)$ is quasi-isomorphic to $\HC_*(M)$, the usual +The complex $K_*(M)$ is homotopy equivalent to $\HC_*(M)$, the usual Hochschild complex of $M$. \end{prop} \begin{proof} @@ -91,7 +98,8 @@ (Here $C\otimes C$ denotes the free $C$-$C$-bimodule with one generator.) That is, $\HC_*(C\otimes C)$ is -quasi-isomorphic to its $0$-th homology (which in turn, by \ref{item:hochschild-coinvariants}, is just $C$) via the quotient map $\HC_0 \onto \HH_0$. +quasi-isomorphic to its $0$-th homology (which in turn, by \ref{item:hochschild-coinvariants} +above, is just $C$) via the quotient map $\HC_0 \onto \HH_0$. \end{enumerate} (Together, these just say that Hochschild homology is `the derived functor of coinvariants'.) We'll first recall why these properties are characteristic. diff -r d13df7f3b2de -r 1acb5f508cf6 text/ncat.tex --- a/text/ncat.tex Wed Mar 03 20:17:52 2010 +0000 +++ b/text/ncat.tex Fri Mar 05 20:27:08 2010 +0000 @@ -1082,6 +1082,7 @@ \subsection{The $n{+}1$-category of sphere modules} +\label{ssec:spherecat} In this subsection we define an $n{+}1$-category $\cS$ of ``sphere modules" whose objects correspond to $n$-categories.