text/evmap.tex
changeset 85 ffcd1a5eafd8
parent 84 c3aace2330ac
child 86 cf67ae4abeb1
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   299 Note that on $G_*^{i,m+1} \subeq G_*^{i,m}$, we have defined two maps,
   299 Note that on $G_*^{i,m+1} \subeq G_*^{i,m}$, we have defined two maps,
   300 call them $e_{i,m}$ and $e_{i,m+1}$.
   300 call them $e_{i,m}$ and $e_{i,m+1}$.
   301 An easy variation on the above lemma shows that $e_{i,m}$ and $e_{i,m+1}$ are $m$-th 
   301 An easy variation on the above lemma shows that $e_{i,m}$ and $e_{i,m+1}$ are $m$-th 
   302 order homotopic.
   302 order homotopic.
   303 
   303 
       
   304 Next we show how to homotope chains in $CD_*(X)\ot \bc_*(X)$ to one of the 
       
   305 $G_*^{i,m}$.
       
   306 Choose a monotone decreasing sequence of real numbers $\gamma_j$ converging to zero.
       
   307 Let $\cU_j$ denote the open cover of $X$ by balls of radius $\gamma_j$.
       
   308 Let $h_j: CD_*(X)\to CD_*(X)$ be a chain map homotopic to the identity whose image is spanned by diffeomorphisms with support compatible with $\cU_j$, as described in Lemma \ref{xxxxx}.
       
   309 Recall that $h_j$ and also its homotopy back to the identity do not increase
       
   310 supports.
       
   311 Define
       
   312 \[
       
   313 	g_j \deq h_j\circ h_{j-1} \circ \cdots \circ h_1 .
       
   314 \]
       
   315 The next lemma says that for all generators $p\ot b$ we can choose $j$ large enough so that
       
   316 $g_j(p)\ot b$ lies in $G_*^{i,m}$, for arbitrary $m$ and sufficiently large $i$ 
       
   317 (depending on $b$, $n = \deg(p)$ and $m$).
       
   318 
       
   319 \begin{lemma}
       
   320 Fix a blob diagram $b$, a homotopy order $m$ and a degree $n$ for $CD_*(X)$.
       
   321 Then there exists a constant $k_{bmn}$ such that for all $i \ge k_{bmn}$
       
   322 there exists another constant $j_i$ such that for all $j \ge j_i$ and all $p\in CD_n(X)$ 
       
   323 we have $g_j(p)\ot b \in G_*^{i,m}$.
       
   324 \end{lemma}
       
   325 
       
   326 \begin{proof}
       
   327 Let $c$ be a subset of the blobs of $b$.
       
   328 There exists $l > 0$ such that $\Nbd_u(c)$ is homeomorphic to $|c|$ for all $u < l$ 
       
   329 and all such $c$.
       
   330 (Here we are using a piecewise smoothness assumption for $\bd c$).
       
   331 
       
   332 Let $r = \deg(b)$.
       
   333 
       
   334 Choose $k = k_{bmn}$ such that
       
   335 \[
       
   336 	(r+n+m+1)\ep_k < l
       
   337 \]
       
   338 and
       
   339 \[
       
   340 	n\cdot (3\delta_k\cdot(r+n+m+1)) < \ep_k .
       
   341 \]
       
   342 Let $i \ge k_{bmn}$.
       
   343 Choose $j = j_i$ so that
       
   344 \[
       
   345 	3\cdot(r+n+m+1)\gamma_j < \ep_i
       
   346 \]
       
   347 and also so that for any subset $S\sub X$ of diameter less than or equal to 
       
   348 $2n\gamma_j$ we have that $\Nbd_u(S)$ is
       
   349 \end{proof}
       
   350 
       
   351 
   304 
   352 
   305 \medskip
   353 \medskip
   306 
   354 
   307 \noop{
   355 \noop{
   308 
   356 
   309 
       
   310 \begin{lemma}
   357 \begin{lemma}
   311 
   358 
   312 \end{lemma}
   359 \end{lemma}
   313 \begin{proof}
   360 \begin{proof}
   314 
   361 
   315 \end{proof}
   362 \end{proof}
   316 
   363 
   317 
       
   318 }
   364 }
   319 
   365 
   320 
   366 
   321 \nn{to be continued....}
   367 \nn{to be continued....}
   322 
   368