text/evmap.tex
changeset 545 8f33a46597c4
parent 544 24be062a87a1
child 548 a91691886cbc
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544:24be062a87a1 545:8f33a46597c4
    19 
    19 
    20 The most convenient way to prove that maps $e_{XY}$ with the desired properties exist is to 
    20 The most convenient way to prove that maps $e_{XY}$ with the desired properties exist is to 
    21 introduce a homotopy equivalent alternate version of the blob complex, $\btc_*(X)$,
    21 introduce a homotopy equivalent alternate version of the blob complex, $\btc_*(X)$,
    22 which is more amenable to this sort of action.
    22 which is more amenable to this sort of action.
    23 Recall from Remark \ref{blobsset-remark} that blob diagrams
    23 Recall from Remark \ref{blobsset-remark} that blob diagrams
    24 have the structure of a sort-of-simplicial set. \nn{need a more conventional sounding name: `polyhedral set'?}
    24 have the structure of a cone-product set.
    25 Blob diagrams can also be equipped with a natural topology, which converts this
    25 Blob diagrams can also be equipped with a natural topology, which converts this
    26 sort-of-simplicial set into a sort-of-simplicial space.
    26 cone-product set into a cone-product space.
    27 Taking singular chains of this space we get $\btc_*(X)$.
    27 Taking singular chains of this space we get $\btc_*(X)$.
    28 The details are in \S \ref{ss:alt-def}.
    28 The details are in \S \ref{ss:alt-def}.
    29 We also prove a useful result (Lemma \ref{small-blobs-b}) which says that we can assume that
    29 We also prove a useful result (Lemma \ref{small-blobs-b}) which says that we can assume that
    30 blobs are small with respect to any fixed open cover.
    30 blobs are small with respect to any fixed open cover.
    31 
    31 
   214 \end{proof}
   214 \end{proof}
   215 
   215 
   216 
   216 
   217 \medskip
   217 \medskip
   218 
   218 
   219 Next we define the sort-of-simplicial space version of the blob complex, $\btc_*(X)$.
   219 Next we define the cone-product space version of the blob complex, $\btc_*(X)$.
   220 First we must specify a topology on the set of $k$-blob diagrams, $\BD_k$.
   220 First we must specify a topology on the set of $k$-blob diagrams, $\BD_k$.
   221 We give $\BD_k$ the finest topology such that
   221 We give $\BD_k$ the finest topology such that
   222 \begin{itemize}
   222 \begin{itemize}
   223 \item For any $b\in \BD_k$ the action map $\Homeo(X) \to \BD_k$, $f \mapsto f(b)$ is continuous.
   223 \item For any $b\in \BD_k$ the action map $\Homeo(X) \to \BD_k$, $f \mapsto f(b)$ is continuous.
   224 \item \nn{don't we need something for collaring maps?}
   224 \item \nn{don't we need something for collaring maps?}
   490 \subsection{[older version still hanging around]}
   490 \subsection{[older version still hanging around]}
   491 \label{ss:old-evmap-remnants}
   491 \label{ss:old-evmap-remnants}
   492 
   492 
   493 \nn{should comment at the start about any assumptions about smooth, PL etc.}
   493 \nn{should comment at the start about any assumptions about smooth, PL etc.}
   494 
   494 
   495 \nn{should maybe mention alternate def of blob complex (sort-of-simplicial space instead of
   495 \nn{should maybe mention alternate def of blob complex (cone-product space instead of
   496 sort-of-simplicial set) where this action would be easy}
   496 cone-product set) where this action would be easy}
   497 
   497 
   498 Let $CH_*(X, Y)$ denote $C_*(\Homeo(X \to Y))$, the singular chain complex of
   498 Let $CH_*(X, Y)$ denote $C_*(\Homeo(X \to Y))$, the singular chain complex of
   499 the space of homeomorphisms
   499 the space of homeomorphisms
   500 between the $n$-manifolds $X$ and $Y$ (any given singular chain extends a fixed homeomorphism $\bd X \to \bd Y$).
   500 between the $n$-manifolds $X$ and $Y$ (any given singular chain extends a fixed homeomorphism $\bd X \to \bd Y$).
   501 We also will use the abbreviated notation $CH_*(X) \deq CH_*(X, X)$.
   501 We also will use the abbreviated notation $CH_*(X) \deq CH_*(X, X)$.