diff -r edcf5835b3dd -r 553808396b6f text/blobdef.tex --- a/text/blobdef.tex Sun Feb 06 18:31:17 2011 -0800 +++ b/text/blobdef.tex Sun Feb 06 20:54:10 2011 -0800 @@ -33,9 +33,11 @@ to define fields on these pieces. We of course define $\bc_0(X) = \cF(X)$. -(If $X$ has nonempty boundary, instead define $\bc_0(X; c) = \cF(X; c)$ for each $c \in \cF(\bdy X)$. +In other words, $\bc_0(X)$ is just the vector space of all fields on $X$. + +(If $X$ has nonempty boundary, instead define $\bc_0(X; c) = \cF(X; c)$ for $c \in \cF(\bdy X)$. +The blob complex $\bc_*(X; c)$ will depend on a fixed boundary condition $c\in \cF(\bdy X)$. We'll omit such boundary conditions from the notation in the rest of this section.) -In other words, $\bc_0(X)$ is just the vector space of all fields on $X$. We want the vector space $\bc_1(X)$ to capture ``the space of all local relations that can be imposed on $\bc_0(X)$". @@ -148,8 +150,8 @@ \item For any (possibly empty) configuration of blobs on an $n$-ball $D$, we can add $D$ itself as an outermost blob. (This is used in the proof of Proposition \ref{bcontract}.) -\item If $X'$ is obtained from $X$ by gluing, then any permissible configuration of blobs -on $X$ gives rise to a permissible configuration on $X'$. +\item If $X\sgl$ is obtained from $X$ by gluing, then any permissible configuration of blobs +on $X$ gives rise to a permissible configuration on $X\sgl$. (This is necessary for Proposition \ref{blob-gluing}.) \end{itemize} Combining these two operations can give rise to configurations of blobs whose complement in $X$ is not @@ -166,8 +168,8 @@ \end{align*} Here $A \cup B = [0,1] \times [-1,1] \times [0,1]$ and $C \cup D = [-1,0] \times [-1,1] \times [0,1]$. Now, $\{A\}$ is a valid configuration of blobs in $A \cup B$, -and $\{C\}$ is a valid configuration of blobs in $C \cup D$, -so we must allow $\{A, C\}$ as a configuration of blobs in $[-1,1]^2 \times [0,1]$. +and $\{D\}$ is a valid configuration of blobs in $C \cup D$, +so we must allow $\{A, D\}$ as a configuration of blobs in $[-1,1]^2 \times [0,1]$. Note however that the complement is not a manifold. \end{example} @@ -244,7 +246,7 @@ \label{defn:blobs} The $k$-th vector space $\bc_k(X)$ of the \emph{blob complex} of $X$ is the direct sum over all configurations of $k$ blobs in $X$ of the vector space of $k$-blob diagrams with that configuration, -modulo identifying the vector spaces for configurations that only differ by a permutation of the balls +modulo identifying the vector spaces for configurations that only differ by a permutation of the blobs by the sign of that permutation. The differential $\bc_k(X) \to \bc_{k-1}(X)$ is, as above, the signed sum of ways of forgetting one blob from the configuration, preserving the field $r$: @@ -263,11 +265,6 @@ is immediately obvious from the definition. A homeomorphism acts in an obvious way on blobs and on fields. -We define the {\it support} of a blob diagram $b$, $\supp(b) \sub X$, -to be the union of the blobs of $b$. -For $y \in \bc_*(X)$ with $y = \sum c_i b_i$ ($c_i$ a non-zero number, $b_i$ a blob diagram), -we define $\supp(y) \deq \bigcup_i \supp(b_i)$. - \begin{remark} \label{blobsset-remark} \rm We note that blob diagrams in $X$ have a structure similar to that of a simplicial set, but with simplices replaced by a more general class of combinatorial shapes.