text/a_inf_blob.tex
changeset 744 0405b70c95cd
parent 685 8efbd2730ef9
child 746 481eba2ddbc9
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741:6de42a06468e 744:0405b70c95cd
   190 Roughly speaking, $(a, K)$ is just $a$ chopped up into little pieces, and 
   190 Roughly speaking, $(a, K)$ is just $a$ chopped up into little pieces, and 
   191 $\psi$ glues those pieces back together, yielding $a$.
   191 $\psi$ glues those pieces back together, yielding $a$.
   192 We have $\psi(r) = 0$ since $\psi$ is zero on $(\ge 1)$-simplices.
   192 We have $\psi(r) = 0$ since $\psi$ is zero on $(\ge 1)$-simplices.
   193  
   193  
   194 Second, $\phi\circ\psi$ is the identity up to homotopy by another argument based on the method of acyclic models.
   194 Second, $\phi\circ\psi$ is the identity up to homotopy by another argument based on the method of acyclic models.
   195 To each generator $(b, \ol{K})$ of $G_*$ we associate the acyclic subcomplex $D(b)$ defined above.
   195 To each generator $(b, \ol{K})$ of $\cl{\cC_F}(Y)$ we associate the acyclic subcomplex $D(b)$ defined above.
   196 Both the identity map and $\phi\circ\psi$ are compatible with this
   196 Both the identity map and $\phi\circ\psi$ are compatible with this
   197 collection of acyclic subcomplexes, so by the usual method of acyclic models argument these two maps
   197 collection of acyclic subcomplexes, so by the usual method of acyclic models argument these two maps
   198 are homotopic.
   198 are homotopic.
   199 
   199 
   200 This concludes the proof of Theorem \ref{thm:product}.
   200 This concludes the proof of Theorem \ref{thm:product}.
   246 (c.f. \cite{MR2079378}).
   246 (c.f. \cite{MR2079378}).
   247 Call this a $k$-category over $Y$.
   247 Call this a $k$-category over $Y$.
   248 A fiber bundle $F\to E\to Y$ gives an example of a $k$-category over $Y$:
   248 A fiber bundle $F\to E\to Y$ gives an example of a $k$-category over $Y$:
   249 assign to $p:D\to Y$ the blob complex $\bc_*(p^*(E))$, if $\dim(D) = k$,
   249 assign to $p:D\to Y$ the blob complex $\bc_*(p^*(E))$, if $\dim(D) = k$,
   250 or the fields $\cE(p^*(E))$, if $\dim(D) < k$.
   250 or the fields $\cE(p^*(E))$, if $\dim(D) < k$.
   251 ($p^*(E)$ denotes the pull-back bundle over $D$.)
   251 (Here $p^*(E)$ denotes the pull-back bundle over $D$.)
   252 Let $\cF_E$ denote this $k$-category over $Y$.
   252 Let $\cF_E$ denote this $k$-category over $Y$.
   253 We can adapt the homotopy colimit construction (based decompositions of $Y$ into balls) to
   253 We can adapt the homotopy colimit construction (based decompositions of $Y$ into balls) to
   254 get a chain complex $\cl{\cF_E}(Y)$.
   254 get a chain complex $\cl{\cF_E}(Y)$.
   255 The proof of Theorem \ref{thm:product} goes through essentially unchanged 
   255 The proof of Theorem \ref{thm:product} goes through essentially unchanged 
   256 to show that
   256 to show the following result.
   257 \begin{thm}
   257 \begin{thm}
   258 Let $F \to E \to Y$ be a fiber bundle and let $\cF_E$ be the $k$-category over $Y$ defined above.
   258 Let $F \to E \to Y$ be a fiber bundle and let $\cF_E$ be the $k$-category over $Y$ defined above.
   259 Then
   259 Then
   260 \[
   260 \[
   261 	\bc_*(E) \simeq \cl{\cF_E}(Y) .
   261 	\bc_*(E) \simeq \cl{\cF_E}(Y) .
   268 Let $M\to Y$ be a map, with $\dim(M) = n$ and $\dim(Y) = k$.
   268 Let $M\to Y$ be a map, with $\dim(M) = n$ and $\dim(Y) = k$.
   269 Call a map $D^j\to Y$ ``good" with respect to $M$ if the fibered product
   269 Call a map $D^j\to Y$ ``good" with respect to $M$ if the fibered product
   270 $D\widetilde{\times} M$ is a manifold of dimension $n-k+j$ with a collar structure along the boundary of $D$.
   270 $D\widetilde{\times} M$ is a manifold of dimension $n-k+j$ with a collar structure along the boundary of $D$.
   271 (If $D\to Y$ is an embedding then $D\widetilde{\times} M$ is just the part of $M$
   271 (If $D\to Y$ is an embedding then $D\widetilde{\times} M$ is just the part of $M$
   272 lying above $D$.)
   272 lying above $D$.)
   273 We can define a $k$-category $\cF_M$ based on maps of balls into $Y$ which a re good with respect to $M$.
   273 We can define a $k$-category $\cF_M$ based on maps of balls into $Y$ which are good with respect to $M$.
   274 We can again adapt the homotopy colimit construction to
   274 We can again adapt the homotopy colimit construction to
   275 get a chain complex $\cl{\cF_M}(Y)$.
   275 get a chain complex $\cl{\cF_M}(Y)$.
   276 The proof of Theorem \ref{thm:product} again goes through essentially unchanged 
   276 The proof of Theorem \ref{thm:product} again goes through essentially unchanged 
   277 to show that
   277 to show that
   278 \begin{thm}
   278 \begin{thm}