text/ncat.tex
changeset 859 76a569bb2cec
parent 858 1fc5fff34251
child 861 84bb5ab4c85c
equal deleted inserted replaced
858:1fc5fff34251 859:76a569bb2cec
  2369 For each pair of $n$-categories in $L_0$, $L_1$ could contain no 0-sphere modules at all or 
  2369 For each pair of $n$-categories in $L_0$, $L_1$ could contain no 0-sphere modules at all or 
  2370 it could contain several.
  2370 it could contain several.
  2371 The only requirement is that each $k$-sphere module be a module for a $k$-sphere $n{-}k$-category
  2371 The only requirement is that each $k$-sphere module be a module for a $k$-sphere $n{-}k$-category
  2372 constructed out of labels taken from $L_j$ for $j<k$.
  2372 constructed out of labels taken from $L_j$ for $j<k$.
  2373 
  2373 
       
  2374 We remind the reader again that $\cS = \cS_{\{L_i\}, \{z_Y\}}$ depends on 
       
  2375 the choice of $L_i$ above as well as the choice of 
       
  2376 families of inner products below.
       
  2377 
  2374 We now define $\cS(X)$, for $X$ a ball of dimension at most $n$, to be the set of all 
  2378 We now define $\cS(X)$, for $X$ a ball of dimension at most $n$, to be the set of all 
  2375 cell-complexes $K$ embedded in $X$, with the codimension-$j$ parts of $(X, K)$ labeled
  2379 cell-complexes $K$ embedded in $X$, with the codimension-$j$ parts of $(X, K)$ labeled
  2376 by elements of $L_j$.
  2380 by elements of $L_j$.
  2377 As described above, we can think of each decorated $k$-ball as defining a $k{-}1$-sphere module
  2381 As described above, we can think of each decorated $k$-ball as defining a $k{-}1$-sphere module
  2378 for the $n{-}k{+}1$-category associated to its decorated boundary.
  2382 for the $n{-}k{+}1$-category associated to its decorated boundary.
  2394 making arbitrary choices of incoming and outgoing boundaries for each $n$-ball. 
  2398 making arbitrary choices of incoming and outgoing boundaries for each $n$-ball. 
  2395 The additional duality assumptions are needed to prove independence of our definition from these choices.
  2399 The additional duality assumptions are needed to prove independence of our definition from these choices.
  2396 
  2400 
  2397 Let $X$ be an $n{+}1$-ball, and let $c$ be a decoration of its boundary
  2401 Let $X$ be an $n{+}1$-ball, and let $c$ be a decoration of its boundary
  2398 by a cell complex labeled by 0- through $n$-morphisms, as above.
  2402 by a cell complex labeled by 0- through $n$-morphisms, as above.
  2399 Choose an $n{-}1$-sphere $E\sub \bd X$ which divides
  2403 Choose an $n{-}1$-sphere $E\sub \bd X$, transverse to $c$, which divides
  2400 $\bd X$ into ``incoming" and ``outgoing" boundary $\bd_-X$ and $\bd_+X$.
  2404 $\bd X$ into ``incoming" and ``outgoing" boundary $\bd_-X$ and $\bd_+X$.
  2401 Let $E_c$ denote $E$ decorated by the restriction of $c$ to $E$.
  2405 Let $E_c$ denote $E$ decorated by the restriction of $c$ to $E$.
  2402 Recall from above the associated 1-category $\cS(E_c)$.
  2406 Recall from above the associated 1-category $\cS(E_c)$.
  2403 We can also have $\cS(E_c)$ modules $\cS(\bd_-X_c)$ and $\cS(\bd_+X_c)$.
  2407 We can also have $\cS(E_c)$ modules $\cS(\bd_-X_c)$ and $\cS(\bd_+X_c)$.
  2404 Define
  2408 Define