text/ncat.tex
changeset 348 b2fab3bf491b
parent 347 14643c4931bc
child 352 38da35694123
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347:14643c4931bc 348:b2fab3bf491b
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   651 \nn{should also include example of ncats coming from TQFTs, or refer ahead to where we discuss that example}
   651 \nn{should also include example of ncats coming from TQFTs, or refer ahead to where we discuss that example}
   652 
   652 
   653 \newcommand{\Bord}{\operatorname{Bord}}
   653 \newcommand{\Bord}{\operatorname{Bord}}
   654 \begin{example}[The bordism $n$-category, plain version]
   654 \begin{example}[The bordism $n$-category, plain version]
       
   655 \label{ex:bord-cat}
   655 \rm
   656 \rm
   656 \label{ex:bordism-category}
   657 \label{ex:bordism-category}
   657 For a $k$-ball $X$, $k<n$, define $\Bord^n(X)$ to be the set of all $k$-dimensional
   658 For a $k$-ball $X$, $k<n$, define $\Bord^n(X)$ to be the set of all $k$-dimensional
   658 submanifolds $W$ of $X\times \Real^\infty$ such that the projection $W \to X$ is transverse
   659 submanifolds $W$ of $X\times \Real^\infty$ such that the projection $W \to X$ is transverse
   659 to $\bd X$.
   660 to $\bd X$.
   717 There's no way for the blob complex to magically recover all the data of $\pi^\infty_{\leq 0}(T) \iso C_* T$.
   718 There's no way for the blob complex to magically recover all the data of $\pi^\infty_{\leq 0}(T) \iso C_* T$.
   718 
   719 
   719 \begin{example}[The bordism $n$-category, $A_\infty$ version]
   720 \begin{example}[The bordism $n$-category, $A_\infty$ version]
   720 \rm
   721 \rm
   721 \label{ex:bordism-category-ainf}
   722 \label{ex:bordism-category-ainf}
   722 blah blah \nn{to do...}
   723 As in Example \ref{ex:bord-cat}, for $X$ a $k$-ball, $k<n$, we define $\Bord^{n,\infty}(X)$
       
   724 to be the set of all $k$-dimensional
       
   725 submanifolds $W$ of $X\times \Real^\infty$ such that the projection $W \to X$ is transverse
       
   726 to $\bd X$.
       
   727 For an $n$-ball $X$ with boundary condition $c$ 
       
   728 define $\Bord^{n,\infty}(X; c)$ to be the space of all $k$-dimensional
       
   729 submanifolds $W$ of $X\times \Real^\infty$ such that 
       
   730 $W$ coincides with $c$ at $\bd X \times \Real^\infty$.
       
   731 (The topology on this space is induced by ambient isotopy rel boundary.
       
   732 This is homotopy equivalent to a disjoint union of copies $\mathrm{B}\!\Homeo(W')$, where
       
   733 $W'$ runs though representatives of homeomorphism types of such manifolds.)
       
   734 \nn{check this}
   723 \end{example}
   735 \end{example}
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   727 Let $\cE\cB_n$ be the operad of smooth embeddings of $k$ (little)
   739 Let $\cE\cB_n$ be the operad of smooth embeddings of $k$ (little)
   762 --- composition and $\Diff(X\to X')$ action ---
   774 --- composition and $\Diff(X\to X')$ action ---
   763 also comes from the $\cE\cB_n$ action on $A$.
   775 also comes from the $\cE\cB_n$ action on $A$.
   764 \nn{should we spell this out?}
   776 \nn{should we spell this out?}
   765 
   777 
   766 \nn{Should remark that this is just Lurie's topological chiral homology construction
   778 \nn{Should remark that this is just Lurie's topological chiral homology construction
   767 applied to $n$-balls (check this).}
   779 applied to $n$-balls (check this).
       
   780 Hmmm... Does Lurie do both framed and unframed cases?}
   768 \end{example}
   781 \end{example}
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