text/a_inf_blob.tex
changeset 303 2252c53bd449
parent 291 9b8b474e272c
child 306 06f06de6f133
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302:52309e058a95 303:2252c53bd449
   277 Think of $\pi^\infty_{\leq n}(T)$ as encoding everything you would ever
   277 Think of $\pi^\infty_{\leq n}(T)$ as encoding everything you would ever
   278 want to know about spaces of maps of $k$-balls into $T$ ($k\le n$).
   278 want to know about spaces of maps of $k$-balls into $T$ ($k\le n$).
   279 To simplify notation, let $\cT = \pi^\infty_{\leq n}(T)$.
   279 To simplify notation, let $\cT = \pi^\infty_{\leq n}(T)$.
   280 
   280 
   281 \begin{thm} \label{thm:map-recon}
   281 \begin{thm} \label{thm:map-recon}
   282 $\cB^\cT(M) \simeq C_*(\Maps(M\to T))$.
   282 The blob complex for $M$ with coefficients in the fundamental $A_\infty$ $n$-category for $T$ is quasi-isomorphic to singular chains on maps from $M$ to $T$.
       
   283 $$\cB^\cT(M) \simeq C_*(\Maps(M\to T)).$$
   283 \end{thm}
   284 \end{thm}
       
   285 \begin{rem}
       
   286 \nn{This just isn't true, Lurie doesn't do this! I just heard this from Ricardo...}
       
   287 Lurie has shown in \cite{0911.0018} that the topological chiral homology of an $n$-manifold $M$ with coefficients in \nn{a certain $E_n$ algebra constructed from $T$} recovers  the same space of singular chains on maps from $M$ to $T$, with the additional hypothesis that $T$ is $n-1$-connected. This extra hypothesis is not surprising, in view of the idea that an $E_n$ algebra is roughly equivalent data as an $A_\infty$ $n$-category which is trivial at all but the topmost level.
       
   288 \end{rem}
       
   289 
   284 \begin{proof}
   290 \begin{proof}
   285 We begin by constructing chain map $g: \cB^\cT(M) \to C_*(\Maps(M\to T))$.
   291 We begin by constructing chain map $g: \cB^\cT(M) \to C_*(\Maps(M\to T))$.
   286 We then use \ref{extension_lemma_b} to show that $g$ induces isomorphisms on homology.
   292 We then use \ref{extension_lemma_b} to show that $g$ induces isomorphisms on homology.
   287 
   293 
   288 Recall that the homotopy colimit $\cB^\cT(M)$ is constructed out of a series of
   294 Recall that the homotopy colimit $\cB^\cT(M)$ is constructed out of a series of