diff -r ba4ddbc41c15 -r 79f7b1bd7b1a text/appendixes/famodiff.tex --- a/text/appendixes/famodiff.tex Tue May 25 07:26:36 2010 -0700 +++ b/text/appendixes/famodiff.tex Tue May 25 16:50:55 2010 -0700 @@ -8,9 +8,8 @@ unity $\{r_\alpha\}$. (That is, $r_\alpha : X \to [0,1]$; $r_\alpha(x) = 0$ if $x\notin U_\alpha$; for fixed $x$, $r_\alpha(x) \ne 0$ for only finitely many $\alpha$; and $\sum_\alpha r_\alpha = 1$.) -Since $X$ is compact, we will further assume that $r_\alpha \ne 0$ (globally) -for only finitely -many $\alpha$. +Since $X$ is compact, we will further assume that $r_\alpha = 0$ (globally) +for all but finitely many $\alpha$. Let \[ @@ -29,8 +28,8 @@ generators which are adapted. \begin{lemma} \label{basic_adaptation_lemma} -The $f: P\times X \to T$, as above. -The there exists +Let $f: P\times X \to T$, as above. +Then there exists \[ F: I \times P\times X \to T \] @@ -41,6 +40,9 @@ the restrictions $F(1, \cdot, \cdot) : D_i\times X\to T$ are all adapted to $\cU$. \item If $f$ has support $S\sub X$, then $F: (I\times P)\times X\to T$ (a $k{+}1$-parameter family of maps) also has support $S$. +Furthermore, if $Q\sub\bd P$ is a convex linear subpolyhedron of $\bd P$ and $f$ restricted to $Q$ +has support $S'$, then +$F: (I\times Q)\times X\to T$ also has support $S'$. \item If for all $p\in P$ we have $f(p, \cdot):X\to T$ is a [immersion, diffeomorphism, PL homeomorphism, bi-Lipschitz homeomorphism] then the same is true of $F(t, p, \cdot)$ for all $t\in I$ and $p\in P$. @@ -68,7 +70,7 @@ sufficiently fine as described below. \def\jj{\tilde{L}} -Let $L$ be a common refinement all the $K_\alpha$'s. +Let $L$ be a common refinement of all the $K_\alpha$'s. Let $\jj$ denote the handle decomposition of $P$ corresponding to $L$. Each $i$-handle $C$ of $\jj$ has an $i$-dimensional tangential coordinate and, more importantly for our purposes, a $k{-}i$-dimensional normal coordinate. @@ -76,6 +78,10 @@ corresponding $i$-handles of $\jj$. For each (top-dimensional) $k$-cell $C$ of each $K_\alpha$, choose a point $p(C) \in C \sub P$. +If $C$ meets a subpolyhedron $Q$ of $\bd P$, we require that $p(C)\in Q$. +(It follows that if $C$ meets both $Q$ and $Q'$, then $p(C)\in Q\cap Q'$. +This puts some mild constraints on the choice of $K_\alpha$.) + Let $D$ be a $k$-handle of $\jj$. For each $\alpha$ let $C(D, \alpha)$ be the $k$-cell of $K_\alpha$ which contains $D$ and let $p(D, \alpha) = p(C(D, \alpha))$. @@ -129,6 +135,7 @@ \end{equation} This completes the definition of $u: I \times P \times X \to P$. +Note that if $Q\sub \bd P$ is a convex linear subpolyhedron, then $u(I\times Q\times X) \sub Q$. \medskip @@ -158,6 +165,13 @@ F(t, p, x) = f(u(t,p,x),x) = f(u(t',p',x),x) = F(t',p',x) \] for all $(t,p)$ and $(t',p')$ in $I\times P$. +Similarly, if $f(q,x) = f(q',x)$ for all $q,q'\in Q\sub \bd P$, +then +\[ + F(t, q, x) = f(u(t,q,x),x) = f(u(t',q',x),x) = F(t',q',x) +\] +for all $(t,q)$ and $(t',q')$ in $I\times Q$. +(Recall that we arranged above that $u(I\times Q\times X) \sub Q$.) \medskip @@ -207,20 +221,22 @@ Then $G_*$ is a strong deformation retract of $CM_*(X\to T)$. \end{lemma} \begin{proof} -\nn{my current idea is too messy, so I'm going to wait and hopefully think -of a cleaner proof} -\noop{ -If suffices to show that -... -Lemma \ref{basic_adaptation_lemma} -... -} +If suffices to show that given a generator $f:P\times X\to T$ of $CM_k(X\to T)$ with +$\bd f \in G_{k-1}$ there exists $h\in CM_{k+1}(X\to T)$ with $\bd h = f + g$ and $g \in G_k$. +This is exactly what Lemma \ref{basic_adaptation_lemma} +gives us. +More specifically, let $\bd P = \sum Q_i$, with each $Q_i\in G_{k-1}$. +Let $F: I\times P\times X\to T$ be the homotopy constructed in Lemma \ref{basic_adaptation_lemma}. +Then $\bd F$ is equal to $f$ plus $F(1, \cdot, \cdot)$ plus the restrictions of $F$ to $I\times Q_i$. +Part 2 of Lemma \ref{basic_adaptation_lemma} says that $F(1, \cdot, \cdot)\in G_k$, +while part 3 of Lemma \ref{basic_adaptation_lemma} says that the restrictions to $I\times Q_i$ are in $G_k$. \end{proof} \medskip \nn{need to clean up references from the main text to the lemmas of this section} +%%%%%% Lo, \noop{...} \noop{ \medskip