text/basic_properties.tex
changeset 417 d3b05641e7ca
parent 409 291f82fb79b5
child 426 8aca80203f9d
equal deleted inserted replaced
416:c06a899bd1f0 417:d3b05641e7ca
    87 $r$ be the restriction of $b$ to $X\setminus S$.
    87 $r$ be the restriction of $b$ to $X\setminus S$.
    88 Note that $S$ is a disjoint union of balls.
    88 Note that $S$ is a disjoint union of balls.
    89 Assign to $b$ the acyclic (in positive degrees) subcomplex $T(b) \deq r\bullet\bc_*(S)$.
    89 Assign to $b$ the acyclic (in positive degrees) subcomplex $T(b) \deq r\bullet\bc_*(S)$.
    90 Note that if a diagram $b'$ is part of $\bd b$ then $T(B') \sub T(b)$.
    90 Note that if a diagram $b'$ is part of $\bd b$ then $T(B') \sub T(b)$.
    91 Both $f$ and the identity are compatible with $T$ (in the sense of acyclic models), 
    91 Both $f$ and the identity are compatible with $T$ (in the sense of acyclic models), 
    92 so $f$ and the identity map are homotopic. \nn{We should actually have a section with a definition of `compatible' and this statement as a lemma}
    92 so $f$ and the identity map are homotopic. \nn{We should actually have a section with a definition of ``compatible" and this statement as a lemma}
    93 \end{proof}
    93 \end{proof}
    94 
    94 
    95 For the next proposition we will temporarily restore $n$-manifold boundary
    95 For the next proposition we will temporarily restore $n$-manifold boundary
    96 conditions to the notation.
    96 conditions to the notation.
    97 
    97 
   109 \eq{
   109 \eq{
   110     \gl: \bigoplus_a \bc_*(X; a, a, c) \to \bc_*(X\sgl; c\sgl).
   110     \gl: \bigoplus_a \bc_*(X; a, a, c) \to \bc_*(X\sgl; c\sgl).
   111 }
   111 }
   112 The sum is over all fields $a$ on $Y$ compatible at their
   112 The sum is over all fields $a$ on $Y$ compatible at their
   113 ($n{-}2$-dimensional) boundaries with $c$.
   113 ($n{-}2$-dimensional) boundaries with $c$.
   114 `Natural' means natural with respect to the actions of diffeomorphisms.
   114 ``Natural" means natural with respect to the actions of diffeomorphisms.
   115 }
   115 }
   116 
   116 
   117 This map is very far from being an isomorphism, even on homology.
   117 This map is very far from being an isomorphism, even on homology.
   118 We fix this deficit in Section \ref{sec:gluing} below.
   118 We fix this deficit in Section \ref{sec:gluing} below.