text/ncat.tex
changeset 741 6de42a06468e
parent 739 da7ac7d30f30
child 750 4b1f08238bae
equal deleted inserted replaced
740:1708a3f23612 741:6de42a06468e
  1275 \end{module-axiom}
  1275 \end{module-axiom}
  1276 
  1276 
  1277 Given $c\in\cl\cM(\bd M)$, let $\cM(M; c) \deq \bd^{-1}(c)$.
  1277 Given $c\in\cl\cM(\bd M)$, let $\cM(M; c) \deq \bd^{-1}(c)$.
  1278 
  1278 
  1279 If the $n$-category $\cC$ is enriched over some other category (e.g.\ vector spaces),
  1279 If the $n$-category $\cC$ is enriched over some other category (e.g.\ vector spaces),
  1280 then $\cM(M; c)$ should be an object in that category for each marked $n$-ball $M$
  1280 then for each marked $n$-ball $M=(B,N)$ and $c\in \cC(\bd B \setminus N)$, the set $\cM(M; c)$ should be an object in that category.
  1281 and $c\in \cC(\bd M)$.
       
  1282 
  1281 
  1283 \begin{lem}[Boundary from domain and range]
  1282 \begin{lem}[Boundary from domain and range]
  1284 {Let $H = M_1 \cup_E M_2$, where $H$ is a marked $k{-}1$-hemisphere ($1\le k\le n$),
  1283 {Let $H = M_1 \cup_E M_2$, where $H$ is a marked $k{-}1$-hemisphere ($1\le k\le n$),
  1285 $M_i$ is a marked $k{-}1$-ball, and $E = M_1\cap M_2$ is a marked $k{-}2$-hemisphere.
  1284 $M_i$ is a marked $k{-}1$-ball, and $E = M_1\cap M_2$ is a marked $k{-}2$-hemisphere.
  1286 Let $\cM(M_1) \times_{\cM(E)} \cM(M_2)$ denote the fibered product of the 
  1285 Let $\cM(M_1) \times_{\cM(E)} \cM(M_2)$ denote the fibered product of the 
  1305 
  1304 
  1306 Note that combining the various boundary and restriction maps above
  1305 Note that combining the various boundary and restriction maps above
  1307 (for both modules and $n$-categories)
  1306 (for both modules and $n$-categories)
  1308 we have for each marked $k$-ball $(B, N)$ and each $k{-}1$-ball $Y\sub \bd B \setmin N$
  1307 we have for each marked $k$-ball $(B, N)$ and each $k{-}1$-ball $Y\sub \bd B \setmin N$
  1309 a natural map from a subset of $\cM(B, N)$ to $\cC(Y)$.
  1308 a natural map from a subset of $\cM(B, N)$ to $\cC(Y)$.
  1310 The subset is the subset of morphisms which are appropriately splittable (transverse to the
  1309 This subset $\cM(B,N)\trans{\bdy Y}$ is the subset of morphisms which are appropriately splittable (transverse to the
  1311 cutting submanifolds).
  1310 cutting submanifolds).
  1312 This fact will be used below.
  1311 This fact will be used below.
  1313 
  1312 
  1314 In our example, the various restriction and gluing maps above come from
  1313 In our example, the various restriction and gluing maps above come from
  1315 restricting and gluing maps into $T$.
  1314 restricting and gluing maps into $T$.
  1331 \begin{module-axiom}[Module composition]
  1330 \begin{module-axiom}[Module composition]
  1332 {Let $M = M_1 \cup_Y M_2$, where $M$, $M_1$ and $M_2$ are marked $k$-balls (with $0\le k\le n$)
  1331 {Let $M = M_1 \cup_Y M_2$, where $M$, $M_1$ and $M_2$ are marked $k$-balls (with $0\le k\le n$)
  1333 and $Y = M_1\cap M_2$ is a marked $k{-}1$-ball.
  1332 and $Y = M_1\cap M_2$ is a marked $k{-}1$-ball.
  1334 Let $E = \bd Y$, which is a marked $k{-}2$-hemisphere.
  1333 Let $E = \bd Y$, which is a marked $k{-}2$-hemisphere.
  1335 Note that each of $M$, $M_1$ and $M_2$ has its boundary split into two marked $k{-}1$-balls by $E$.
  1334 Note that each of $M$, $M_1$ and $M_2$ has its boundary split into two marked $k{-}1$-balls by $E$.
  1336 We have restriction (domain or range) maps $\cM(M_i)_E \to \cM(Y)$.
  1335 We have restriction (domain or range) maps $\cM(M_i)\trans E \to \cM(Y)$.
  1337 Let $\cM(M_1)_E \times_{\cM(Y)} \cM(M_2)_E$ denote the fibered product of these two maps. 
  1336 Let $\cM(M_1) \trans E \times_{\cM(Y)} \cM(M_2) \trans E$ denote the fibered product of these two maps. 
  1338 Then (axiom) we have a map
  1337 Then (axiom) we have a map
  1339 \[
  1338 \[
  1340 	\gl_Y : \cM(M_1)_E \times_{\cM(Y)} \cM(M_2)_E \to \cM(M)_E
  1339 	\gl_Y : \cM(M_1) \trans E \times_{\cM(Y)} \cM(M_2) \trans E \to \cM(M) \trans E
  1341 \]
  1340 \]
  1342 which is natural with respect to the actions of homeomorphisms, and also compatible with restrictions
  1341 which is natural with respect to the actions of homeomorphisms, and also compatible with restrictions
  1343 to the intersection of the boundaries of $M$ and $M_i$.
  1342 to the intersection of the boundaries of $M$ and $M_i$.
  1344 If $k < n$,
  1343 If $k < n$,
  1345 or if $k=n$ and we are in the $A_\infty$ case, 
  1344 or if $k=n$ and we are in the $A_\infty$ case, 
  1355 \begin{module-axiom}[$n$-category action]
  1354 \begin{module-axiom}[$n$-category action]
  1356 {Let $M = X \cup_Y M'$, where $M$ and $M'$ are marked $k$-balls ($0\le k\le n$),
  1355 {Let $M = X \cup_Y M'$, where $M$ and $M'$ are marked $k$-balls ($0\le k\le n$),
  1357 $X$ is a plain $k$-ball,
  1356 $X$ is a plain $k$-ball,
  1358 and $Y = X\cap M'$ is a $k{-}1$-ball.
  1357 and $Y = X\cap M'$ is a $k{-}1$-ball.
  1359 Let $E = \bd Y$, which is a $k{-}2$-sphere.
  1358 Let $E = \bd Y$, which is a $k{-}2$-sphere.
  1360 We have restriction maps $\cM(M')_E \to \cC(Y)$ and $\cC(X)_E\to \cC(Y)$.
  1359 We have restriction maps $\cM(M') \trans E \to \cC(Y)$ and $\cC(X) \trans E\to \cC(Y)$.
  1361 Let $\cC(X)\trans E \times_{\cC(Y)} \cM(M')_E$ denote the fibered product of these two maps. 
  1360 Let $\cC(X)\trans E \times_{\cC(Y)} \cM(M') \trans E$ denote the fibered product of these two maps. 
  1362 Then (axiom) we have a map
  1361 Then (axiom) we have a map
  1363 \[
  1362 \[
  1364 	\gl_Y :\cC(X)\trans E \times_{\cC(Y)} \cM(M')_E \to \cM(M)_E
  1363 	\gl_Y :\cC(X)\trans E \times_{\cC(Y)} \cM(M')\trans E \to \cM(M) \trans E
  1365 \]
  1364 \]
  1366 which is natural with respect to the actions of homeomorphisms, and also compatible with restrictions
  1365 which is natural with respect to the actions of homeomorphisms, and also compatible with restrictions
  1367 to the intersection of the boundaries of $X$ and $M'$.
  1366 to the intersection of the boundaries of $X$ and $M'$.
  1368 If $k < n$,
  1367 If $k < n$,
  1369 or if $k=n$ and we are in the $A_\infty$ case, 
  1368 or if $k=n$ and we are in the $A_\infty$ case,