text/a_inf_blob.tex
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    13 When we need to distinguish between the new and old definitions, we will refer to the 
    13 When we need to distinguish between the new and old definitions, we will refer to the 
    14 new-fangled and old-fashioned blob complex.
    14 new-fangled and old-fashioned blob complex.
    15 
    15 
    16 \medskip
    16 \medskip
    17 
    17 
       
    18 \subsection{The small blob complex}
       
    19 
       
    20 \input{text/smallblobs}
       
    21 
       
    22 \subsection{A product formula}
       
    23 
    18 Let $M^n = Y^k\times F^{n-k}$.  
    24 Let $M^n = Y^k\times F^{n-k}$.  
    19 Let $C$ be a plain $n$-category.
    25 Let $C$ be a plain $n$-category.
    20 Let $\cF$ be the $A_\infty$ $k$-category which assigns to a $k$-ball
    26 Let $\cF$ be the $A_\infty$ $k$-category which assigns to a $k$-ball
    21 $X$ the old-fashioned blob complex $\bc_*(X\times F)$.
    27 $X$ the old-fashioned blob complex $\bc_*(X\times F)$.
    22 
    28 
    23 \begin{thm} \label{product_thm}
    29 \begin{thm} \label{product_thm}
    24 The old-fashioned blob complex $\bc_*^C(Y\times F)$ is homotopy equivalent to the
    30 The old-fashioned blob complex $\bc_*^C(Y\times F)$ is homotopy equivalent to the
    25 new-fangled blob complex $\bc_*^\cF(Y)$.
    31 new-fangled blob complex $\bc_*^\cF(Y)$.
    26 \end{thm}
    32 \end{thm}
    27 
    33 
    28 \input{text/smallblobs}
    34 
    29 
    35 
    30 \begin{proof}[Proof of Theorem \ref{product_thm}]
    36 \begin{proof}[Proof of Theorem \ref{product_thm}]
    31 We will use the concrete description of the colimit from Subsection \ref{ss:ncat_fields}.
    37 We will use the concrete description of the colimit from Subsection \ref{ss:ncat_fields}.
    32 
    38 
    33 First we define a map 
    39 First we define a map 
   211 Apply Theorem \ref{product_thm} with the fiber $F$ equal to a point.
   217 Apply Theorem \ref{product_thm} with the fiber $F$ equal to a point.
   212 \end{proof}
   218 \end{proof}
   213 
   219 
   214 \medskip
   220 \medskip
   215 
   221 
       
   222 \subsection{A gluing theorem}
       
   223 \label{sec:gluing}
       
   224 
   216 Next we prove a gluing theorem.
   225 Next we prove a gluing theorem.
   217 Let $X$ be a closed $k$-manifold with a splitting $X = X'_1\cup_Y X'_2$.
   226 Let $X$ be a closed $k$-manifold with a splitting $X = X'_1\cup_Y X'_2$.
   218 We will need an explicit collar on $Y$, so rewrite this as
   227 We will need an explicit collar on $Y$, so rewrite this as
   219 $X = X_1\cup (Y\times J) \cup X_2$.
   228 $X = X_1\cup (Y\times J) \cup X_2$.
   220 \nn{need figure}
   229 \nn{need figure}
   228 $m$-ball $(D, H)$ either fields on $(D\times Y) \cup (H\times X_i)$ (if $m+k < n$)
   237 $m$-ball $(D, H)$ either fields on $(D\times Y) \cup (H\times X_i)$ (if $m+k < n$)
   229 or the blob complex $\bc_*((D\times Y) \cup (H\times X_i))$ (if $m+k = n$).
   238 or the blob complex $\bc_*((D\times Y) \cup (H\times X_i))$ (if $m+k = n$).
   230 \end{itemize}
   239 \end{itemize}
   231 
   240 
   232 \begin{thm}
   241 \begin{thm}
       
   242 \label{thm:gluing}
   233 $\bc(X) \cong \bc(X_1) \otimes_{\bc(Y), J} \bc(X_2)$.
   243 $\bc(X) \cong \bc(X_1) \otimes_{\bc(Y), J} \bc(X_2)$.
   234 \end{thm}
   244 \end{thm}
   235 
   245 
   236 \begin{proof}
   246 \begin{proof}
   237 The proof is similar to that of Theorem \ref{product_thm}.
   247 The proof is similar to that of Theorem \ref{product_thm}.
   251 \end{proof}
   261 \end{proof}
   252 
   262 
   253 This establishes Property \ref{property:gluing}.
   263 This establishes Property \ref{property:gluing}.
   254 
   264 
   255 \medskip
   265 \medskip
       
   266 
       
   267 \subsection{Reconstructing mapping spaces}
   256 
   268 
   257 The next theorem shows how to reconstruct a mapping space from local data.
   269 The next theorem shows how to reconstruct a mapping space from local data.
   258 Let $T$ be a topological space, let $M$ be an $n$-manifold, 
   270 Let $T$ be a topological space, let $M$ be an $n$-manifold, 
   259 and recall the $A_\infty$ $n$-category $\pi^\infty_{\leq n}(T)$ 
   271 and recall the $A_\infty$ $n$-category $\pi^\infty_{\leq n}(T)$ 
   260 of Example \ref{ex:chains-of-maps-to-a-space}.
   272 of Example \ref{ex:chains-of-maps-to-a-space}.