text/hochschild.tex
changeset 886 c570a7a75b07
parent 885 61541264d4b3
child 894 3f38383f26d3
equal deleted inserted replaced
885:61541264d4b3 886:c570a7a75b07
   342 and there are labels $c_i$ at the labeled points outside the blob.
   342 and there are labels $c_i$ at the labeled points outside the blob.
   343 We know that
   343 We know that
   344 $$\sum_j d_{j,1} \tensor \cdots \tensor d_{j,k_j} \tensor m_j \tensor d_{j,1}' \tensor \cdots \tensor d_{j,k'_j}' \in \ker(\DirectSum_{k,k'} C^{\tensor k} \tensor M \tensor C^{\tensor k'} \to M),$$
   344 $$\sum_j d_{j,1} \tensor \cdots \tensor d_{j,k_j} \tensor m_j \tensor d_{j,1}' \tensor \cdots \tensor d_{j,k'_j}' \in \ker(\DirectSum_{k,k'} C^{\tensor k} \tensor M \tensor C^{\tensor k'} \to M),$$
   345 and so
   345 and so
   346 \begin{align*}
   346 \begin{align*}
   347 \ev(\bdy y) & = \sum_j m_j d_{j,1}' \cdots d_{j,k'_j}' c_1 \cdots c_k d_{j,1} \cdots d_{j,k_j} \\
   347 \pi\left(\ev(\bdy y)\right) & = \pi\left(\sum_j m_j d_{j,1}' \cdots d_{j,k'_j}' c_1 \cdots c_k d_{j,1} \cdots d_{j,k_j}\right) \\
   348             & = \sum_j d_{j,1} \cdots d_{j,k_j} m_j d_{j,1}' \cdots d_{j,k'_j}' c_1 \cdots c_k \\
   348             & = \pi\left(\sum_j d_{j,1} \cdots d_{j,k_j} m_j d_{j,1}' \cdots d_{j,k'_j}' c_1 \cdots c_k\right) \\
   349             & = 0
   349             & = 0
   350 \end{align*}
   350 \end{align*}
   351 where this time we use the fact that we're mapping to $\coinv{M}$, not just $M$.
   351 where this time we use the fact that we're mapping to $\coinv{M}$, not just $M$.
   352 
   352 
   353 The map $\pi \compose \ev: H_0(K_*(M)) \to \coinv{M}$ is clearly 
   353 The map $\pi \compose \ev: H_0(K_*(M)) \to \coinv{M}$ is clearly