* universal property of tangent bundle
@ 1999-07-19 15:09 Nikita Danilov
0 siblings, 0 replies; 2+ messages in thread
From: Nikita Danilov @ 1999-07-19 15:09 UTC (permalink / raw)
To: categories
Dear category people,
Given an object M in the ``normal'' category of finitely dimensional
smooth manifolds Man (not in SDG sense), what it the universal property
of the tangent bundle TM?
So far, I found only the following:
For every manifold M there is a functor F:I -> Man0, where Man0 is
category of open areas in R^n and smooth mapping, such that M=Colim F,
F corresponding to the atlas on M and M is represented as a result of
gluing instances of R^n in the atlas. This functor can be trivially
modified (by multiplying its values on objects on R^n and modifying
morphisms appropriately) to get functor TF:I -> Man0, such that
TM=Colim TF.
But this doesn't seem satisfactory because:
1. Construction of TF follows one particular construction of TM as a
set of triples (x,(U,f),h) where x \in U, (U,f) is in atlas and h \in
R^n with appropriate points identified.
2. I hope there should be universal construction with \pi: TM -> M as
universal arrow.
3. As tangent bundle is so ubiquitous there should be nice universal
property for it.
With regards,
N. Danilov.
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: universal property of tangent bundle
@ 1999-08-02 10:22 Kirill Mackenzie
0 siblings, 0 replies; 2+ messages in thread
From: Kirill Mackenzie @ 1999-08-02 10:22 UTC (permalink / raw)
To: categories
In addition to Madame Ehresmann's references, there is in
Spivak's Comprehensive Introduction... an abstract
characterization of the tangent bundle ( removed from the
main text in the second edition `due to the pressure of public
distaste')
Kirill Mackenzie
>
> Given an object M in the ``normal'' category of finitely dimensional
> smooth manifolds Man (not in SDG sense), what it the universal property
> of the tangent bundle TM?
>
> So far, I found only the following:
>
> For every manifold M there is a functor F:I -> Man0, where Man0 is
> category of open areas in R^n and smooth mapping, such that M=Colim F,
> F corresponding to the atlas on M and M is represented as a result of
> gluing instances of R^n in the atlas. This functor can be trivially
> modified (by multiplying its values on objects on R^n and modifying
> morphisms appropriately) to get functor TF:I -> Man0, such that
> TM=Colim TF.
>
> But this doesn't seem satisfactory because:
>
> 1. Construction of TF follows one particular construction of TM as a
> set of triples (x,(U,f),h) where x \in U, (U,f) is in atlas and h \in
> R^n with appropriate points identified.
>
> 2. I hope there should be universal construction with \pi: TM -> M as
> universal arrow.
>
> 3. As tangent bundle is so ubiquitous there should be nice universal
> property for it.
>
> With regards,
> N. Danilov.
>
>
>
>
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