Talk:Normal bordism - definitions (Ex)

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where we identify $(\xi_0,M_0,i_0,f_0,\overline{f_0})\sim(\xi_1,M_1,i_1,f_1,\overline{f_1})$ iff
where we identify $(\xi_0,M_0,i_0,f_0,\overline{f_0})\sim(\xi_1,M_1,i_1,f_1,\overline{f_1})$ iff
1) there exists $W$ compact manifold of dimension $n+1$ such that $\partial W=\partial_0W\amalg\partial_1W$
+
1) There exists a compact manifold $W$ of dimension $n+1$ whose boundary can be written as $\partial W=\partial_0W\amalg\partial_1W$.
2) there exists an embedding $I$: $W\to\mathbb{R}^{n+k}\times[0,1]$ such that for $j=0,1$ we have
+
2) There exists an embedding $I$: $W\to\mathbb{R}^{n+k}\times[0,1]$ such that for $j=0,1$ we have
$I^{-1}(\mathbb{R}^{n+k}\times\{j\})=\partial_jW$ and $W$ meets $\mathbb{R}^{n+k}\times\{j\}$ transversally
+
$I^{-1}(\mathbb{R}^{n+k}\times\{j\})=\partial_jW$ and $W$ meets $\mathbb{R}^{n+k}\times\{j\}$ transversally.
3) there exists a vector bundle $\eta$: $E'\to X\times[0,1]$ of rank $k$
+
3) There exists a vector bundle $\eta$: $E'\to X\times[0,1]$ of rank $k$
and for $j=0,1$ there exist vector bundle isomorphisms $(\mathrm{id}_X,H_j)$: $\eta|_{X\times\{j\}}\to\xi_j$
+
and for $j=0,1$ there exist vector bundle isomorphisms $(\mathrm{id}_X,H_j)$: $\eta|_{X\times\{j\}}\to\xi_j$.
4) there exists a bundle map $(F,\overline{F})$: $\nu(W,I)\to\eta$ such that for $j=0,1$ we have $F(\partial_jW)\subset X\times\{j\}$
+
4) There exists a bundle map $(F,\overline{F})$: $\nu(W,I)\to\eta$ such that for $j=0,1$ we have $F(\partial_jW)\subset X\times\{j\}$
and such that $F$: $(W,\partial W)\to(X\times[0,1],X\times\partial[0,1])$
and such that $F$: $(W,\partial W)\to(X\times[0,1],X\times\partial[0,1])$
has degree one as a map between Poincare pairs.
has degree one as a map between Poincare pairs.
5) for $j=0,1$ there exist diffeomorphisms $U_j$: $\mathbb{R}^{n+k}\to\mathbb{R}^{n+k}\times\{j\}$ such that
+
5) For $j=0,1$ there exist diffeomorphisms $U_j$: $\mathbb{R}^{n+k}\to\mathbb{R}^{n+k}\times\{j\}$ such that
a) $U_j|_{M_j}$: $M_j\to\partial_jW$ is a diffeomorphism
a) $U_j|_{M_j}$: $M_j\to\partial_jW$ is a diffeomorphism
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\right\}
\right\}
$$
$$
+
where we identify $(\xi_0,M_0,a_0,f_0,\overline{f_0})\sim(\xi_1,M_1,a_1,f_1,\overline{f_1})$ iff
+
+
1) There exists a compact manifold $W$ of dimension $n+1$ whose boundary can be written as $\partial W=\partial_0W\amalg\partial_1W$.
+
+
2) There exists a vector bundle $\eta$: $E'\to X\times[0,1]$ and there exist $b\in\mathbb{N}_0$ and
+
a bundle map $(F,\overline{F})$: $TW\oplus\underline{\mathbb{R}^b}\to\eta$
+
such that for $j=0,1$ we have $F(\partial_jW)\subset X\times\{j\}$
+
and such that $F$: $(W,\partial W)\to(X\times[0,1],X\times\partial[0,1])$
+
has degree one as a map between Poincare pairs.
+
+
3) For $j=0,1$ there exist diffeomorphisms $U_j$: $M_j\to\partial_jW$ such that $F\circ U_j=f_j$.
+
+
4) For $j=0,1$ there exist bundle isomorphisms $(\mathrm{id}_X,V_j)$: $\xi_j\oplus\underline{\mathbb{R}^{b-a_j+1}}\to\eta|_{X\times\{j\}}$
+
such that $V_j\circ(\overline{f_j}\oplus\mathrm{id}_{\underline{\mathbb{R}^{b-a_j+1}}})=\overline{F}|_{\partial_jW}\circ(TU_j\oplus n_j\oplus\mathrm{id}_{\underline{\mathbb{R}^b}})$.
+
Here $TU_j$: $TM_j\to TW|_{\partial_jW}$ is the differential of $U_j$ and $n_j$: $\underline{\mathbb{R}}\to TW|_{\partial_jW}$ is given by an inward normal field of $TW|_{\partial_jW}$.
</wikitex>
</wikitex>

Revision as of 11:44, 2 April 2012

In both parts let X be a connected finite Poincare complex of dimension n and let k\geq0.

Part 1

The following definition of the set of normal maps \mathcal{N}_n(X,k) is similar to [Lück2001, Definition 3.46]. We define

\displaystyle  \mathcal{N}_n(X,k):= \left\{ [\xi,M,i,f,\overline{f}] | \begin{array}{l} \xi\textrm{ vector bundle of rank }k\textrm{ over }X,\,  M\textrm{ closed manifold of dimension }n,\, i:\,M\to\mathbb{R}^{n+k}\textrm{ embedding},\, (f,\overline{f}):\,\nu(M,i)\to\xi\textrm{ bundle map},\, f\textrm{ of degree }1 \end{array} \right\}

where we identify (\xi_0,M_0,i_0,f_0,\overline{f_0})\sim(\xi_1,M_1,i_1,f_1,\overline{f_1}) iff

1) There exists a compact manifold W of dimension n+1 whose boundary can be written as \partial W=\partial_0W\amalg\partial_1W.

2) There exists an embedding I: W\to\mathbb{R}^{n+k}\times[0,1] such that for j=0,1 we have I^{-1}(\mathbb{R}^{n+k}\times\{j\})=\partial_jW and W meets \mathbb{R}^{n+k}\times\{j\} transversally.

3) There exists a vector bundle \eta: E'\to X\times[0,1] of rank k and for j=0,1 there exist vector bundle isomorphisms (\mathrm{id}_X,H_j): \eta|_{X\times\{j\}}\to\xi_j.

4) There exists a bundle map (F,\overline{F}): \nu(W,I)\to\eta such that for j=0,1 we have F(\partial_jW)\subset X\times\{j\} and such that F: (W,\partial W)\to(X\times[0,1],X\times\partial[0,1]) has degree one as a map between Poincare pairs.

5) For j=0,1 there exist diffeomorphisms U_j: \mathbb{R}^{n+k}\to\mathbb{R}^{n+k}\times\{j\} such that

a) U_j|_{M_j}: M_j\to\partial_jW is a diffeomorphism

b) F\circ U_j|_{M_j}=f_j

c) the induced bundle map (U_j,\nu(U_j)): \nu(M_j,i_j)\to\nu(W,I)|_{\partial_jW} satisfies H_j\circ\overline{F}\circ\nu(U_j)=\overline{f_j}.

Part 2

The following definition of the set of tangential normal maps \mathcal{N}^T_n(X,k) differs from [Lück2001, Definition 3.50]. We define

\displaystyle  \mathcal{N}^T_n(X,k):= \left\{ [\xi,M,a,f,\overline{f}] | \begin{array}{l} \xi\textrm{ vector bundle of rank }k\textrm{ over }X,\,  M\textrm{ closed manifold of dimension }n,\, a\in\mathbb{N}_0,\, (f,\overline{f}):\,TM\oplus\underline{\mathbb{R}^a}\to\xi\textrm{ bundle map},\, f\textrm{ of degree }1 \end{array} \right\}

where we identify (\xi_0,M_0,a_0,f_0,\overline{f_0})\sim(\xi_1,M_1,a_1,f_1,\overline{f_1}) iff

1) There exists a compact manifold W of dimension n+1 whose boundary can be written as \partial W=\partial_0W\amalg\partial_1W.

2) There exists a vector bundle \eta: E'\to X\times[0,1] and there exist b\in\mathbb{N}_0 and a bundle map (F,\overline{F}): TW\oplus\underline{\mathbb{R}^b}\to\eta such that for j=0,1 we have F(\partial_jW)\subset X\times\{j\} and such that F: (W,\partial W)\to(X\times[0,1],X\times\partial[0,1]) has degree one as a map between Poincare pairs.

3) For j=0,1 there exist diffeomorphisms U_j: M_j\to\partial_jW such that F\circ U_j=f_j.

4) For j=0,1 there exist bundle isomorphisms (\mathrm{id}_X,V_j): \xi_j\oplus\underline{\mathbb{R}^{b-a_j+1}}\to\eta|_{X\times\{j\}} such that V_j\circ(\overline{f_j}\oplus\mathrm{id}_{\underline{\mathbb{R}^{b-a_j+1}}})=\overline{F}|_{\partial_jW}\circ(TU_j\oplus n_j\oplus\mathrm{id}_{\underline{\mathbb{R}^b}}). Here TU_j: TM_j\to TW|_{\partial_jW} is the differential of U_j and n_j: \underline{\mathbb{R}}\to TW|_{\partial_jW} is given by an inward normal field of TW|_{\partial_jW}.

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