pnas/pnas.tex
changeset 611 fd6e53389f2c
parent 608 455106e40a61
child 612 871dffc348ab
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    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:
   372 \]
   371 \]
   373 \item
   372 \item
   374 Product morphisms are compatible with gluing.
   373 Product morphisms are compatible with gluing.
   375 Let $\pi:E\to X$, $\pi_1:E_1\to X_1$, and $\pi_2:E_2\to X_2$ 
   374 Let $\pi:E\to X$, $\pi_1:E_1\to X_1$, and $\pi_2:E_2\to X_2$ 
   376 be pinched products with $E = E_1\cup E_2$.
   375 be pinched products with $E = E_1\cup E_2$.
   377 Let $a\in \cC(X)$, and let $a_i$ denote the restriction of $a$ to $X_i\sub X$.
   376 Let $a\in \cC(X)$, and let $a_i$ denote the restriction of $a$ to $X_i\subset X$.
   378 Then 
   377 Then 
   379 \[
   378 \[
   380 	\pi^*(a) = \pi_1^*(a_1)\bullet \pi_2^*(a_2) .
   379 	\pi^*(a) = \pi_1^*(a_1)\bullet \pi_2^*(a_2) .
   381 \]
   380 \]
   382 \item
   381 \item
   399 \end{enumerate}
   398 \end{enumerate}
   400 } %%% end \noop %%%
   399 } %%% end \noop %%%
   401 \end{axiom}
   400 \end{axiom}
   402 
   401 
   403 To state the next axiom we need the notion of {\it collar maps} on $k$-morphisms.
   402 To state the next axiom we need the notion of {\it collar maps} on $k$-morphisms.
   404 Let $X$ be a $k$-ball and $Y\sub\bd X$ be a $(k{-}1)$-ball.
   403 Let $X$ be a $k$-ball and $Y\subset\bd X$ be a $(k{-}1)$-ball.
   405 Let $J$ be a 1-ball.
   404 Let $J$ be a 1-ball.
   406 Let $Y\times_p J$ denote $Y\times J$ pinched along $(\bd Y)\times J$.
   405 Let $Y\times_p J$ denote $Y\times J$ pinched along $(\bd Y)\times J$.
   407 A collar map is an instance of the composition
   406 A collar map is an instance of the composition
   408 \[
   407 \[
   409 	\cC(X) \to \cC(X\cup_Y (Y\times_p J)) \to \cC(X) ,
   408 	\cC(X) \to \cC(X\cup_Y (Y\times_p J)) \to \cC(X) ,
   432 
   431 
   433 \begin{axiom}[\textup{\textbf{[$A_\infty$ version]}} Families of homeomorphisms act in dimension $n$.]
   432 \begin{axiom}[\textup{\textbf{[$A_\infty$ version]}} Families of homeomorphisms act in dimension $n$.]
   434 \label{axiom:families}
   433 \label{axiom:families}
   435 For each $n$-ball $X$ and each $c\in \cl{\cC}(\bd X)$ we have a map of chain complexes
   434 For each $n$-ball $X$ and each $c\in \cl{\cC}(\bd X)$ we have a map of chain complexes
   436 \[
   435 \[
   437 	C_*(\Homeo_\bd(X))\ot \cC(X; c) \to \cC(X; c) .
   436 	C_*(\Homeo_\bd(X))\tensor \cC(X; c) \to \cC(X; c) .
   438 \]
   437 \]
   439 These action maps are required to be associative up to homotopy,
   438 These action maps are required to be associative up to homotopy,
   440 and also compatible with composition (gluing) in the sense that
   439 and also compatible with composition (gluing) in the sense that
   441 a diagram like the one in Theorem \ref{thm:CH} commutes.
   440 a diagram like the one in Theorem \ref{thm:CH} commutes.
   442 \end{axiom}
   441 \end{axiom}
   462 If $X$ is an $n$-ball, identify two such string diagrams if they evaluate to the same $n$-morphism of $C$.
   461 If $X$ is an $n$-ball, identify two such string diagrams if they evaluate to the same $n$-morphism of $C$.
   463 Boundary restrictions and gluing are again straightforward to define.
   462 Boundary restrictions and gluing are again straightforward to define.
   464 Define product morphisms via product cell decompositions.
   463 Define product morphisms via product cell decompositions.
   465 
   464 
   466 
   465 
   467 \nn{also do bordism category}
       
   468 
   466 
   469 \subsection{The blob complex}
   467 \subsection{The blob complex}
   470 \subsubsection{Decompositions of manifolds}
   468 \subsubsection{Decompositions of manifolds}
   471 
   469 
   472 A \emph{ball decomposition} of $W$ is a 
   470 A \emph{ball decomposition} of $W$ is a 
   495 
   493 
   496 An $n$-category $\cC$ determines 
   494 An $n$-category $\cC$ determines 
   497 a functor $\psi_{\cC;W}$ from $\cell(W)$ to the category of sets 
   495 a functor $\psi_{\cC;W}$ from $\cell(W)$ to the category of sets 
   498 (possibly with additional structure if $k=n$).
   496 (possibly with additional structure if $k=n$).
   499 Each $k$-ball $X$ of a decomposition $y$ of $W$ has its boundary decomposed into $k{-}1$-balls,
   497 Each $k$-ball $X$ of a decomposition $y$ of $W$ has its boundary decomposed into $k{-}1$-balls,
   500 and there is a subset $\cC(X)\spl \sub \cC(X)$ of morphisms whose boundaries
   498 and there is a subset $\cC(X)\spl \subset \cC(X)$ of morphisms whose boundaries
   501 are splittable along this decomposition.
   499 are splittable along this decomposition.
   502 
   500 
   503 \begin{defn}
   501 \begin{defn}
   504 Define the functor $\psi_{\cC;W} : \cell(W) \to \Set$ as follows.
   502 Define the functor $\psi_{\cC;W} : \cell(W) \to \Set$ as follows.
   505 For a decomposition $x = \bigsqcup_a X_a$ in $\cell(W)$, $\psi_{\cC;W}(x)$ is the subset
   503 For a decomposition $x = \bigsqcup_a X_a$ in $\cell(W)$, $\psi_{\cC;W}(x)$ is the subset
   506 \begin{equation*}
   504 \begin{equation*}
   507 %\label{eq:psi-C}
   505 %\label{eq:psi-C}
   508 	\psi_{\cC;W}(x) \sub \prod_a \cC(X_a)\spl
   506 	\psi_{\cC;W}(x) \subset \prod_a \cC(X_a)\spl
   509 \end{equation*}
   507 \end{equation*}
   510 where the restrictions to the various pieces of shared boundaries amongst the cells
   508 where the restrictions to the various pieces of shared boundaries amongst the cells
   511 $X_a$ 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.
   509 $X_a$ 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.
   512 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 $\cC$.
   510 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 $\cC$.
   513 \end{defn}
   511 \end{defn}
   671 \item For
   669 \item For
   672 any codimension $0$-submanifold $Y \sqcup Y^\text{op} \subset \bdy X$ the following diagram
   670 any codimension $0$-submanifold $Y \sqcup Y^\text{op} \subset \bdy X$ the following diagram
   673 (using the gluing maps described in Property \ref{property:gluing-map}) commutes (up to homotopy).
   671 (using the gluing maps described in Property \ref{property:gluing-map}) commutes (up to homotopy).
   674 \begin{equation*}
   672 \begin{equation*}
   675 \xymatrix@C+0.3cm{
   673 \xymatrix@C+0.3cm{
   676      \CH{X} \otimes \bc_*(X)
   674      \CH{X} \tensor \bc_*(X)
   677         \ar[r]_{e_{X}}  \ar[d]^{\gl^{\Homeo}_Y \otimes \gl_Y}  &
   675         \ar[r]_{e_{X}}  \ar[d]^{\gl^{\Homeo}_Y \tensor \gl_Y}  &
   678             \bc_*(X) \ar[d]_{\gl_Y} \\
   676             \bc_*(X) \ar[d]_{\gl_Y} \\
   679      \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)
   677      \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)
   680 }
   678 }
   681 \end{equation*}
   679 \end{equation*}
   682 \end{enumerate}
   680 \end{enumerate}
   683 
   681 
   684 Futher, this map is associative, in the sense that the following diagram commutes (up to homotopy).
   682 Futher, this map is associative, in the sense that the following diagram commutes (up to homotopy).
   780 We have already defined the action of mapping cylinders, in Theorem \ref{thm:evaluation}, and the action of surgeries is just composition of maps of $A_\infty$-modules. We only need to check that the relations of the $n$-SC operad are satisfied. This follows immediately from the locality of the action of $\CH{-}$ (i.e., that it is compatible with gluing) and associativity.
   778 We have already defined the action of mapping cylinders, in Theorem \ref{thm:evaluation}, and the action of surgeries is just composition of maps of $A_\infty$-modules. We only need to check that the relations of the $n$-SC operad are satisfied. This follows immediately from the locality of the action of $\CH{-}$ (i.e., that it is compatible with gluing) and associativity.
   781 \end{proof} 
   779 \end{proof} 
   782 
   780 
   783 The little disks operad $LD$ is homotopy equivalent to 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 $Hoch^*(C, C)$. The usual Deligne conjecture (proved variously in \cite{hep-th/9403055, MR1805894, MR2064592, MR1805923}) gives a map
   781 The little disks operad $LD$ is homotopy equivalent to 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 $Hoch^*(C, C)$. The usual Deligne conjecture (proved variously in \cite{hep-th/9403055, MR1805894, MR2064592, MR1805923}) gives a map
   784 \[
   782 \[
   785 	C_*(LD_k)\otimes \overbrace{Hoch^*(C, C)\otimes\cdots\otimes Hoch^*(C, C)}^{\text{$k$ copies}}
   783 	C_*(LD_k)\tensor \overbrace{Hoch^*(C, C)\tensor\cdots\tensor Hoch^*(C, C)}^{\text{$k$ copies}}
   786 			\to  Hoch^*(C, C),
   784 			\to  Hoch^*(C, C),
   787 \]
   785 \]
   788 which we now see to be a specialization of Theorem \ref{thm:deligne}.
   786 which we now see to be a specialization of Theorem \ref{thm:deligne}.
   789 
   787 
   790 
   788