diff -r 8a0d4f53367b -r 8c2ed3a951e0 talks/20091108-Riverside/riverside1.tex --- a/talks/20091108-Riverside/riverside1.tex Wed Nov 04 22:43:58 2009 +0000 +++ b/talks/20091108-Riverside/riverside1.tex Fri Nov 06 00:14:01 2009 +0000 @@ -13,7 +13,7 @@ \author[Scott Morrison]{Scott Morrison \\ \texttt{http://tqft.net/} \\ joint work with Kevin Walker} \institute{UC Berkeley / Miller Institute for Basic Research} \title{Blob homology, part $\mathbb{I}$} -\date{Homotopy Theory and Higher Algebraic Structures, UC Riverside, November 10 2009 \\ \url{http://tqft.net/UCR-blobs1}} +\date{Homotopy Theory and Higher Algebraic Structures, UC Riverside, November 10 2009 \\ \begin{description}\item[slides, part $\mathbb{I}$:]\url{http://tqft.net/UCR-blobs1} \item[slides, part $\mathbb{II}$:]\url{http://tqft.net/UCR-blobs2} \item[draft:]\url{http://tqft.net/blobs}\end{description}} \begin{document} @@ -54,7 +54,7 @@ \node[red] (blobs) at (0,0) {$H(\bc_*(\cM; \cC))$}; \uncover<1>{ -\node[blue] (skein) at (4,0) {$A(\cM; \cC)$}; +\node[blue] (skein) at (4,0) {$\cA(\cM; \cC)$}; \node[below=5pt, description] (skein-label) at (skein) {(the usual TQFT Hilbert space)}; \path[->](blobs) edge node[above] {$*= 0$} (skein); } @@ -111,9 +111,33 @@ \end{block} \end{frame} +\begin{frame}{Background: TQFT invariants} +\begin{defn} +A decapitated $n+1$-dimensional TQFT associates a vector space $\cA(\cM)$ to each $n$-manifold $\cM$. +\end{defn} +(`decapitated': no numerical invariants of $n+1$-manifolds.) + +\begin{block}{} +If the manifold has boundary, we get a category. Objects are boundary data, $\Hom{\cA(\cM)}{x}{y} = \cA(\cM; x,y)$. +\end{block} + +\begin{block}{} +We want to extend `all the way down'. The $k$-category associated to the $n-k$-manifold $\cY$ is $\cA(\cY \times B^k)$. +\end{block} + +\begin{defn} +Given an $n$-category $\cC$, the associated TQFT is +\vspace{-3mm} +$$\cA(\cM) = \cF(M) / \ker{ev},$$ + +\vspace{-3mm} +fields modulo fields which evaluate to zero inside some ball. +\end{defn} +\end{frame} + \begin{frame}{\emph{Definition} of the blob complex, $k=0,1$} \begin{block}{Motivation} -A \emph{local} construction, such that when $\cM$ is a ball, $\bc_*(\cM; \cC)$ is a resolution of $A(\cM,; \cC)$. +A \emph{local} construction, such that when $\cM$ is a ball, $\bc_*(\cM; \cC)$ is a resolution of $\cA(\cM,; \cC)$. \end{block} \begin{block}{} @@ -161,7 +185,7 @@ \begin{frame}{Definition, general case} \begin{block}{} -$$\bc_k = \set{\mathfig{0.4}{tempkw/blobkdiagram}}$$ +$$\bc_k = \set{\roundframe{\mathfig{0.7}{definition/k-blobs}}}$$ $k$ blobs, properly nested or disjoint, with ``innermost'' blobs labelled by pasting diagrams that evaluate to zero. \end{block} \begin{block}{} @@ -171,6 +195,27 @@ \end{frame} \section{Properties} +\begin{frame}{Hochschild homology} +\begin{block}{TQFT on $S^1$ is `coinvariants'} +\vspace{-3mm} +$$\cA(S^1, A) = \Complex\set{\roundframe{\mathfig{0.1}{hochschild/m-a-b}}}\scalebox{2}{$/$}\set{\roundframe{\mathfig{0.065}{hochschild/ma}} - \roundframe{\mathfig{0.12}{hochschild/m-a}}} = A/(ab-ba)$$ +\end{block} +\begin{block}{} +The Hochschild complex is `coinvariants of the bar resolution' +\vspace{-2mm} +$$ \cdots \to A \tensor A \tensor A \to A \tensor A \xrightarrow{m \tensor a \mapsto ma-am} A$$ +\end{block} +\begin{thm}[$ \HC_*(A) \iso \bc_*(S^1; A)$] +$$m \tensor a \mapsto +\roundframe{\mathfig{0.35}{hochschild/1-chains}} +$$ +\vspace{-5mm} +\begin{align*} +u_1 & = \mathfig{0.05}{hochschild/u_1-1} - \mathfig{0.05}{hochschild/u_1-2} & u_2 &= \mathfig{0.05}{hochschild/u_2-1} - \mathfig{0.05}{hochschild/u_2-2} +\end{align*} +\end{thm} +\end{frame} + \begin{frame}{An action of $\CH{\cM}$} \begin{thm} There's a chain map