diff -r a96ffd48ea3d -r c6ab12960403 text/ncat.tex --- a/text/ncat.tex Sun Jun 19 21:35:30 2011 -0600 +++ b/text/ncat.tex Tue Jun 21 12:05:16 2011 -0700 @@ -2599,6 +2599,48 @@ Because of the strong duality enjoyed by disklike $n$-categories, the data for such an equivalence lives only in dimensions 1 and $n+1$ (the middle dimensions come along for free), and this data must satisfy identities corresponding to Morse cancellations in $n{+}1$-manifolds. +We will treat this in detail for the $n=2$ case; the case for general $n$ is very similar. + +Let $C$ and $D$ be (unoriented) disklike 2-categories. +Let $\cS$ denote the 3-category of 2-category sphere modules. +The 1-dimensional part of the data for a Morita equivalence between $C$ and $D$ is a 0-sphere module $M = {}_CM_D$ +(categorified bimodule) connecting $C$ and $D$. +Because of the full unoriented symmetry, this can also be thought of as a +0-sphere module ${}_DM_C$ connecting $D$ and $C$. + +We want $M$ to be an equivalence, so we need 2-morphisms in $\cS$ +between ${}_CM_D \otimes_D {}_DM_C$ and the identity 0-sphere module ${}_CC_C$, and similarly +with the roles of $C$ and $D$ reversed. +These 2-morphisms come for free, in the sense of not requiring additional data, since we can take them to be the labeled +cell complexes (cups and caps) in $B^2$ shown in Figure \nn{need figure}. + +We want the 2-morphisms from the previous paragraph to be equivalences, so we need 3-morphisms +between various compositions of these 2-morphisms and various identity 2-morphisms. +Recall that the 3-morphisms of $\cS$ are intertwinors between representations of 1-categories associated +to decorated circles. +Figure \nn{need Figure} shows the intertwinors we need. +Each decorated 2-ball in that figure determines a representation of the 1-category associated to the decorated circle +on the boundary. +This is the 3-dimensional part of the data for the Morita equivalence. +\nn{?? note that, by symmetry, the x and y arrows of Fig xxxx are the same (up to rotation), as are the z and w arrows} + +In order for these 3-morphisms to be equivalences, they must satisfy identities corresponding to Morse cancellations +on 3-manifolds. +These are illustrated in Figure \nn{need figure}. +Each line shows a composition of two intertwinors which we require to be equal to the identity intertwinor. + +For general $n$, we start with an $n$-category 0-sphere module $M$ which is the data for the 1-dimensional +part of the Morita equivalence. +For $2\le k \le n$, the $k$-dimensional parts of the Morita equivalence are various decorated $k$-balls with submanifolds +labeled by $C$, $D$ and $M$; no additional data is needed for these parts. +The $n{+}1$-dimensional part of the equivalence is given by certain intertwinors, and these intertwinors must satisfy +identities corresponding to Morse cancellations in $n{+}1$-manifolds. + + + + + + \noop{ % the following doesn't work; need 2^(k+1) different N's, not 2*(k+1) More specifically, the 1-dimensional part of the data is a 0-sphere module $M = {}_CM_D$ (categorified bimodule) connecting $C$ and $D$. @@ -2609,7 +2651,7 @@ (where $C' = D$ and $D' = C$), and the codimension-1 submanifold separating the positive and negative regions is labeled by $M$. We think of $N^k_{j,E}$ as a $k{+}1$-morphism connecting -} We plan on treating this in more detail in a future paper. \nn{should add a few more details} +}