pnas/pnas.tex
changeset 604 f0dff7f0f337
parent 603 bff9959bdc98
child 605 78db9976b145
equal deleted inserted replaced
603:bff9959bdc98 604:f0dff7f0f337
   397 	\res_D\circ\pi^* = \rho^*\circ\res_Y .
   397 	\res_D\circ\pi^* = \rho^*\circ\res_Y .
   398 \]
   398 \]
   399 \end{enumerate}
   399 \end{enumerate}
   400 } %%% end \noop %%%
   400 } %%% end \noop %%%
   401 \end{axiom}
   401 \end{axiom}
       
   402 
       
   403 To state the next axiom we need the notion of {\it collar maps} on $k$-morphisms.
       
   404 Let $X$ be a $k$-ball and $Y\sub\bd X$ be a $(k{-}1)$-ball.
       
   405 Let $J$ be a 1-ball.
       
   406 Let $Y\times_p J$ denote $Y\times J$ pinched along $(\bd Y)\times J$.
       
   407 A collar map is an instance of the composition
       
   408 \[
       
   409 	\cC(X) \to \cC(X\cup_Y (Y\times_p J)) \to \cC(X) ,
       
   410 \]
       
   411 where the first arrow is gluing with a product morphism on $Y\times_p J$ and
       
   412 the second is induced by a homeomorphism from $X\cup_Y (Y\times_p J)$ to $X$ which restricts
       
   413 to the identity on the boundary.
       
   414 
       
   415 
   402 \begin{axiom}[\textup{\textbf{[plain  version]}} Extended isotopy invariance in dimension $n$.]
   416 \begin{axiom}[\textup{\textbf{[plain  version]}} Extended isotopy invariance in dimension $n$.]
   403 \label{axiom:extended-isotopies}
   417 \label{axiom:extended-isotopies}
   404 Let $X$ be an $n$-ball and $f: X\to X$ be a homeomorphism which restricts
   418 Let $X$ be an $n$-ball and $f: X\to X$ be a homeomorphism which restricts
   405 to the identity on $\bd X$ and isotopic (rel boundary) to the identity.
   419 to the identity on $\bd X$ and isotopic (rel boundary) to the identity.
   406 Then $f$ acts trivially on $\cC(X)$.
   420 Then $f$ acts trivially on $\cC(X)$.
   407 In addition, collar maps act trivially on $\cC(X)$.
   421 In addition, collar maps act trivially on $\cC(X)$.
   408 \end{axiom}
   422 \end{axiom}
   409 
       
   410 \nn{need to define collar maps}
       
   411 
   423 
   412 \smallskip
   424 \smallskip
   413 
   425 
   414 For $A_\infty$ $n$-categories, we replace
   426 For $A_\infty$ $n$-categories, we replace
   415 isotopy invariance with the requirement that families of homeomorphisms act.
   427 isotopy invariance with the requirement that families of homeomorphisms act.