pnas/pnas.tex
changeset 613 5700634d8442
parent 610 357f8673564f
parent 612 871dffc348ab
child 614 ab6bfadab93e
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610:357f8673564f 613:5700634d8442
    72 
    72 
    73 %\newcommand{\mfrac}[2]{\frac{\displaystyle #1}{\displaystyle #2}}
    73 %\newcommand{\mfrac}[2]{\frac{\displaystyle #1}{\displaystyle #2}}
    74 %\def\s{\sigma}
    74 %\def\s{\sigma}
    75 
    75 
    76 \input{preamble}
    76 \input{preamble}
    77 \input{../text/kw_macros}
       
    78 
    77 
    79 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    78 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    80 %% Don't type in anything in the following section:
    79 %% Don't type in anything in the following section:
    81 %%%%%%%%%%%%
    80 %%%%%%%%%%%%
    82 %% For PNAS Only:
    81 %% For PNAS Only:
   378 \]
   377 \]
   379 \item
   378 \item
   380 Product morphisms are compatible with gluing.
   379 Product morphisms are compatible with gluing.
   381 Let $\pi:E\to X$, $\pi_1:E_1\to X_1$, and $\pi_2:E_2\to X_2$ 
   380 Let $\pi:E\to X$, $\pi_1:E_1\to X_1$, and $\pi_2:E_2\to X_2$ 
   382 be pinched products with $E = E_1\cup E_2$.
   381 be pinched products with $E = E_1\cup E_2$.
   383 Let $a\in \cC(X)$, and let $a_i$ denote the restriction of $a$ to $X_i\sub X$.
   382 Let $a\in \cC(X)$, and let $a_i$ denote the restriction of $a$ to $X_i\subset X$.
   384 Then 
   383 Then 
   385 \[
   384 \[
   386 	\pi^*(a) = \pi_1^*(a_1)\bullet \pi_2^*(a_2) .
   385 	\pi^*(a) = \pi_1^*(a_1)\bullet \pi_2^*(a_2) .
   387 \]
   386 \]
   388 \item
   387 \item
   405 \end{enumerate}
   404 \end{enumerate}
   406 } %%% end \noop %%%
   405 } %%% end \noop %%%
   407 \end{axiom}
   406 \end{axiom}
   408 
   407 
   409 To state the next axiom we need the notion of {\it collar maps} on $k$-morphisms.
   408 To state the next axiom we need the notion of {\it collar maps} on $k$-morphisms.
   410 Let $X$ be a $k$-ball and $Y\sub\bd X$ be a $(k{-}1)$-ball.
   409 Let $X$ be a $k$-ball and $Y\subset\bd X$ be a $(k{-}1)$-ball.
   411 Let $J$ be a 1-ball.
   410 Let $J$ be a 1-ball.
   412 Let $Y\times_p J$ denote $Y\times J$ pinched along $(\bd Y)\times J$.
   411 Let $Y\times_p J$ denote $Y\times J$ pinched along $(\bd Y)\times J$.
   413 A collar map is an instance of the composition
   412 A collar map is an instance of the composition
   414 \[
   413 \[
   415 	\cC(X) \to \cC(X\cup_Y (Y\times_p J)) \to \cC(X) ,
   414 	\cC(X) \to \cC(X\cup_Y (Y\times_p J)) \to \cC(X) ,
   438 
   437 
   439 \begin{axiom}[\textup{\textbf{[$A_\infty$ version]}} Families of homeomorphisms act in dimension $n$.]
   438 \begin{axiom}[\textup{\textbf{[$A_\infty$ version]}} Families of homeomorphisms act in dimension $n$.]
   440 \label{axiom:families}
   439 \label{axiom:families}
   441 For each $n$-ball $X$ and each $c\in \cl{\cC}(\bd X)$ we have a map of chain complexes
   440 For each $n$-ball $X$ and each $c\in \cl{\cC}(\bd X)$ we have a map of chain complexes
   442 \[
   441 \[
   443 	C_*(\Homeo_\bd(X))\ot \cC(X; c) \to \cC(X; c) .
   442 	C_*(\Homeo_\bd(X))\tensor \cC(X; c) \to \cC(X; c) .
   444 \]
   443 \]
   445 These action maps are required to be associative up to homotopy,
   444 These action maps are required to be associative up to homotopy,
   446 and also compatible with composition (gluing) in the sense that
   445 and also compatible with composition (gluing) in the sense that
   447 a diagram like the one in Theorem \ref{thm:CH} commutes.
   446 a diagram like the one in Theorem \ref{thm:CH} commutes.
   448 \end{axiom}
   447 \end{axiom}
   467 that is, certain cell complexes embedded in $X$, with the codimension-$j$ cells labeled by $j$-morphisms of $C$.
   466 that is, certain cell complexes embedded in $X$, with the codimension-$j$ cells labeled by $j$-morphisms of $C$.
   468 If $X$ is an $n$-ball, identify two such string diagrams if they evaluate to the same $n$-morphism of $C$.
   467 If $X$ is an $n$-ball, identify two such string diagrams if they evaluate to the same $n$-morphism of $C$.
   469 Boundary restrictions and gluing are again straightforward to define.
   468 Boundary restrictions and gluing are again straightforward to define.
   470 Define product morphisms via product cell decompositions.
   469 Define product morphisms via product cell decompositions.
   471 
   470 
   472 
   471 \subsection{Example (bordism)}
   473 \nn{also do bordism category}
   472 When $X$ is a $k$-ball with $k<n$, $\Bord^n(X)$ is the set of all $k$-dimensional
       
   473 submanifolds $W$ in $X\times \bbR^\infty$ which project to $X$ transversely
       
   474 to $\bd X$.
       
   475 For an $n$-ball $X$ define $\Bord^n(X)$ to be homeomorphism classes rel boundary of such $n$-dimensional submanifolds.
       
   476 
       
   477 There is an $A_\infty$ analogue enriched in topological spaces, where at the top level we take all such submanifolds, rather than homeomorphism classes. For each fixed $\bdy W \subset \bdy X \times \bbR^\infty$, we can topologize the set of submanifolds by ambient isotopy rel boundary.
   474 
   478 
   475 \subsection{The blob complex}
   479 \subsection{The blob complex}
   476 \subsubsection{Decompositions of manifolds}
   480 \subsubsection{Decompositions of manifolds}
   477 
   481 
   478 A \emph{ball decomposition} of $W$ is a 
   482 A \emph{ball decomposition} of $W$ is a 
   501 
   505 
   502 An $n$-category $\cC$ determines 
   506 An $n$-category $\cC$ determines 
   503 a functor $\psi_{\cC;W}$ from $\cell(W)$ to the category of sets 
   507 a functor $\psi_{\cC;W}$ from $\cell(W)$ to the category of sets 
   504 (possibly with additional structure if $k=n$).
   508 (possibly with additional structure if $k=n$).
   505 Each $k$-ball $X$ of a decomposition $y$ of $W$ has its boundary decomposed into $k{-}1$-balls,
   509 Each $k$-ball $X$ of a decomposition $y$ of $W$ has its boundary decomposed into $k{-}1$-balls,
   506 and there is a subset $\cC(X)\spl \sub \cC(X)$ of morphisms whose boundaries
   510 and there is a subset $\cC(X)\spl \subset \cC(X)$ of morphisms whose boundaries
   507 are splittable along this decomposition.
   511 are splittable along this decomposition.
   508 
   512 
   509 \begin{defn}
   513 \begin{defn}
   510 Define the functor $\psi_{\cC;W} : \cell(W) \to \Set$ as follows.
   514 Define the functor $\psi_{\cC;W} : \cell(W) \to \Set$ as follows.
   511 For a decomposition $x = \bigsqcup_a X_a$ in $\cell(W)$, $\psi_{\cC;W}(x)$ is the subset
   515 For a decomposition $x = \bigsqcup_a X_a$ in $\cell(W)$, $\psi_{\cC;W}(x)$ is the subset
   512 \begin{equation*}
   516 \begin{equation*}
   513 %\label{eq:psi-C}
   517 %\label{eq:psi-C}
   514 	\psi_{\cC;W}(x) \sub \prod_a \cC(X_a)\spl
   518 	\psi_{\cC;W}(x) \subset \prod_a \cC(X_a)\spl
   515 \end{equation*}
   519 \end{equation*}
   516 where the restrictions to the various pieces of shared boundaries amongst the cells
   520 where the restrictions to the various pieces of shared boundaries amongst the cells
   517 $X_a$ all agree (this is a fibered product of all the labels of $n$-cells over the labels of $n-1$-cells). When $k=n$, the `subset' and `product' in the above formula should be interpreted in the appropriate enriching category.
   521 $X_a$ all agree (this is a fibered product of all the labels of $n$-cells over the labels of $n-1$-cells). When $k=n$, the `subset' and `product' in the above formula should be interpreted in the appropriate enriching category.
   518 If $x$ is a refinement of $y$, the map $\psi_{\cC;W}(x) \to \psi_{\cC;W}(y)$ is given by the composition maps of $\cC$.
   522 If $x$ is a refinement of $y$, the map $\psi_{\cC;W}(x) \to \psi_{\cC;W}(y)$ is given by the composition maps of $\cC$.
   519 \end{defn}
   523 \end{defn}
   677 \item For
   681 \item For
   678 any codimension $0$-submanifold $Y \sqcup Y^\text{op} \subset \bdy X$ the following diagram
   682 any codimension $0$-submanifold $Y \sqcup Y^\text{op} \subset \bdy X$ the following diagram
   679 (using the gluing maps described in Property \ref{property:gluing-map}) commutes (up to homotopy).
   683 (using the gluing maps described in Property \ref{property:gluing-map}) commutes (up to homotopy).
   680 \begin{equation*}
   684 \begin{equation*}
   681 \xymatrix@C+0.3cm{
   685 \xymatrix@C+0.3cm{
   682      \CH{X} \otimes \bc_*(X)
   686      \CH{X} \tensor \bc_*(X)
   683         \ar[r]_{e_{X}}  \ar[d]^{\gl^{\Homeo}_Y \otimes \gl_Y}  &
   687         \ar[r]_{e_{X}}  \ar[d]^{\gl^{\Homeo}_Y \tensor \gl_Y}  &
   684             \bc_*(X) \ar[d]_{\gl_Y} \\
   688             \bc_*(X) \ar[d]_{\gl_Y} \\
   685      \CH{X \bigcup_Y \selfarrow} \otimes \bc_*(X \bigcup_Y \selfarrow) \ar[r]_<<<<<<<{e_{(X \bigcup_Y \scalebox{0.5}{\selfarrow})}}    & \bc_*(X \bigcup_Y \selfarrow)
   689      \CH{X \bigcup_Y \selfarrow} \tensor \bc_*(X \bigcup_Y \selfarrow) \ar[r]_<<<<<<<{e_{(X \bigcup_Y \scalebox{0.5}{\selfarrow})}}    & \bc_*(X \bigcup_Y \selfarrow)
   686 }
   690 }
   687 \end{equation*}
   691 \end{equation*}
   688 \end{enumerate}
   692 \end{enumerate}
   689 
   693 
   690 Further, this map is associative, in the sense that the following diagram commutes (up to homotopy).
   694 Further, this map is associative, in the sense that the following diagram commutes (up to homotopy).
   810 The little disks operad $LD$ is homotopy equivalent to 
   814 The little disks operad $LD$ is homotopy equivalent to 
   811 \nn{suboperad of}
   815 \nn{suboperad of}
   812 the $n=1$ case of the $n$-SC operad. The blob complex $\bc_*(I, \cC)$ is a bimodule over itself, and the $A_\infty$-bimodule intertwiners are homotopy equivalent to the Hochschild cohains $Hoch^*(C, C)$. 
   816 the $n=1$ case of the $n$-SC operad. The blob complex $\bc_*(I, \cC)$ is a bimodule over itself, and the $A_\infty$-bimodule intertwiners are homotopy equivalent to the Hochschild cohains $Hoch^*(C, C)$. 
   813 The usual Deligne conjecture (proved variously in \cite{hep-th/9403055, MR1805894, MR2064592, MR1805923}) gives a map
   817 The usual Deligne conjecture (proved variously in \cite{hep-th/9403055, MR1805894, MR2064592, MR1805923}) gives a map
   814 \[
   818 \[
   815 	C_*(LD_k)\otimes \overbrace{Hoch^*(C, C)\otimes\cdots\otimes Hoch^*(C, C)}^{\text{$k$ copies}}
   819 	C_*(LD_k)\tensor \overbrace{Hoch^*(C, C)\tensor\cdots\tensor Hoch^*(C, C)}^{\text{$k$ copies}}
   816 			\to  Hoch^*(C, C),
   820 			\to  Hoch^*(C, C),
   817 \]
   821 \]
   818 which we now see to be a specialization of Theorem \ref{thm:deligne}.
   822 which we now see to be a specialization of Theorem \ref{thm:deligne}.
   819 
   823 
   820 
   824