Orientation and line bundle
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I'm stuck on the following problem:
Given $X$ a manifold and $L$ a line bundle over $X$, considerer $Z$
the null-section and define $Or(L) := (L setminus Z) ,
/,mathbb{R}_+^*$. Show that the trivialisation $L_{|U} simeq U times mathbb{R}$ induces a homeomorphism $pi^{-1}(U) simeq U
times Or(mathbb{R})$ (where $Or(mathbb{R})$ is nothing more that
${pm 1 }$), where $pi : L to X$ is the canonical
projection. Conclude that $Or(L)$ is given a unique smooth manifold
structure such that $eta : Or(L) to X$ is a local diffeomorphism.
Here, $eta$ is the continuous surjection induced by $pi$. Indeed, $pi$ is trivially constant over the fibers of the quotient map, so that it goes down continuously to the said quotient $Or(L)$.
Thanks for the help!
differential-geometry
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up vote
0
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favorite
I'm stuck on the following problem:
Given $X$ a manifold and $L$ a line bundle over $X$, considerer $Z$
the null-section and define $Or(L) := (L setminus Z) ,
/,mathbb{R}_+^*$. Show that the trivialisation $L_{|U} simeq U times mathbb{R}$ induces a homeomorphism $pi^{-1}(U) simeq U
times Or(mathbb{R})$ (where $Or(mathbb{R})$ is nothing more that
${pm 1 }$), where $pi : L to X$ is the canonical
projection. Conclude that $Or(L)$ is given a unique smooth manifold
structure such that $eta : Or(L) to X$ is a local diffeomorphism.
Here, $eta$ is the continuous surjection induced by $pi$. Indeed, $pi$ is trivially constant over the fibers of the quotient map, so that it goes down continuously to the said quotient $Or(L)$.
Thanks for the help!
differential-geometry
Something's wrong in the statement here. You mean that $eta^{-1}(U)cong Utimes text{Or}(Bbb R)$?
– Ted Shifrin
6 hours ago
add a comment |
up vote
0
down vote
favorite
up vote
0
down vote
favorite
I'm stuck on the following problem:
Given $X$ a manifold and $L$ a line bundle over $X$, considerer $Z$
the null-section and define $Or(L) := (L setminus Z) ,
/,mathbb{R}_+^*$. Show that the trivialisation $L_{|U} simeq U times mathbb{R}$ induces a homeomorphism $pi^{-1}(U) simeq U
times Or(mathbb{R})$ (where $Or(mathbb{R})$ is nothing more that
${pm 1 }$), where $pi : L to X$ is the canonical
projection. Conclude that $Or(L)$ is given a unique smooth manifold
structure such that $eta : Or(L) to X$ is a local diffeomorphism.
Here, $eta$ is the continuous surjection induced by $pi$. Indeed, $pi$ is trivially constant over the fibers of the quotient map, so that it goes down continuously to the said quotient $Or(L)$.
Thanks for the help!
differential-geometry
I'm stuck on the following problem:
Given $X$ a manifold and $L$ a line bundle over $X$, considerer $Z$
the null-section and define $Or(L) := (L setminus Z) ,
/,mathbb{R}_+^*$. Show that the trivialisation $L_{|U} simeq U times mathbb{R}$ induces a homeomorphism $pi^{-1}(U) simeq U
times Or(mathbb{R})$ (where $Or(mathbb{R})$ is nothing more that
${pm 1 }$), where $pi : L to X$ is the canonical
projection. Conclude that $Or(L)$ is given a unique smooth manifold
structure such that $eta : Or(L) to X$ is a local diffeomorphism.
Here, $eta$ is the continuous surjection induced by $pi$. Indeed, $pi$ is trivially constant over the fibers of the quotient map, so that it goes down continuously to the said quotient $Or(L)$.
Thanks for the help!
differential-geometry
differential-geometry
edited 15 hours ago
asked 17 hours ago
Hermès
1,799612
1,799612
Something's wrong in the statement here. You mean that $eta^{-1}(U)cong Utimes text{Or}(Bbb R)$?
– Ted Shifrin
6 hours ago
add a comment |
Something's wrong in the statement here. You mean that $eta^{-1}(U)cong Utimes text{Or}(Bbb R)$?
– Ted Shifrin
6 hours ago
Something's wrong in the statement here. You mean that $eta^{-1}(U)cong Utimes text{Or}(Bbb R)$?
– Ted Shifrin
6 hours ago
Something's wrong in the statement here. You mean that $eta^{-1}(U)cong Utimes text{Or}(Bbb R)$?
– Ted Shifrin
6 hours ago
add a comment |
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Something's wrong in the statement here. You mean that $eta^{-1}(U)cong Utimes text{Or}(Bbb R)$?
– Ted Shifrin
6 hours ago