text/a_inf_blob.tex
changeset 476 4d0ca2fc4f2b
parent 448 c3c8fb292934
child 512 050dba5e7bdd
equal deleted inserted replaced
475:07c18e2abd8f 476:4d0ca2fc4f2b
    67 Given a decomposition $K$ of $Y$ into $k$-balls $X_i$, let $K\times F$ denote the corresponding
    67 Given a decomposition $K$ of $Y$ into $k$-balls $X_i$, let $K\times F$ denote the corresponding
    68 decomposition of $Y\times F$ into the pieces $X_i\times F$.
    68 decomposition of $Y\times F$ into the pieces $X_i\times F$.
    69 
    69 
    70 Let $G_*\sub \bc_*(Y\times F;C)$ be the subcomplex generated by blob diagrams $a$ such that there
    70 Let $G_*\sub \bc_*(Y\times F;C)$ be the subcomplex generated by blob diagrams $a$ such that there
    71 exists a decomposition $K$ of $Y$ such that $a$ splits along $K\times F$.
    71 exists a decomposition $K$ of $Y$ such that $a$ splits along $K\times F$.
    72 It follows from Proposition \ref{thm:small-blobs} that $\bc_*(Y\times F; C)$ is homotopic to a subcomplex of $G_*$.
    72 It follows from Proposition \ref{thm:small-blobs} that $\bc_*(Y\times F; C)$ 
       
    73 is homotopic to a subcomplex of $G_*$.
    73 (If the blobs of $a$ are small with respect to a sufficiently fine cover then their
    74 (If the blobs of $a$ are small with respect to a sufficiently fine cover then their
    74 projections to $Y$ are contained in some disjoint union of balls.)
    75 projections to $Y$ are contained in some disjoint union of balls.)
    75 Note that the image of $\psi$ is equal to $G_*$.
    76 Note that the image of $\psi$ is equal to $G_*$.
    76 
    77 
    77 We will define $\phi: G_* \to \cl{\cC_F}(Y)$ using the method of acyclic models.
    78 We will define $\phi: G_* \to \cl{\cC_F}(Y)$ using the method of acyclic models.
    93 \begin{lemma} \label{lem:d-a-acyclic}
    94 \begin{lemma} \label{lem:d-a-acyclic}
    94 $D(a)$ is acyclic.
    95 $D(a)$ is acyclic.
    95 \end{lemma}
    96 \end{lemma}
    96 
    97 
    97 \begin{proof}
    98 \begin{proof}
    98 We will prove acyclicity in the first couple of degrees, and \nn{in this draft, at least}
    99 We will prove acyclicity in the first couple of degrees, and 
       
   100 %\nn{in this draft, at least}
    99 leave the general case to the reader.
   101 leave the general case to the reader.
   100 
   102 
   101 Let $K$ and $K'$ be two decompositions (0-simplices) of $Y$ compatible with $a$.
   103 Let $K$ and $K'$ be two decompositions (0-simplices) of $Y$ compatible with $a$.
   102 We want to find 1-simplices which connect $K$ and $K'$.
   104 We want to find 1-simplices which connect $K$ and $K'$.
   103 We might hope that $K$ and $K'$ have a common refinement, but this is not necessarily
   105 We might hope that $K$ and $K'$ have a common refinement, but this is not necessarily