Does \(\tilde{y}^{j}\) depend on \(x^{i}\) in the tangent bundle framework?

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Discussion Overview

The discussion revolves around the relationship between coordinates in the tangent bundle framework, specifically whether \(\tilde{y}^{j}\) depends on \(x^{i}\). Participants explore the implications of changing coordinate systems and the independence of variables in this context.

Discussion Character

  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant describes the tangent bundle and the relationship between local coordinate systems \((x^{i}, y^{i})\) and \((\tilde{x}^{i}, \tilde{y}^{i})\), noting the dependence of \(x^{i}\) on \(\tilde{x}^{j}\) and \(y^{i}\) on \(\tilde{y}^{j}\).
  • The same participant questions whether \(\tilde{y}^{j}\) depends on \(x^{i}\) and seeks the value of \(\frac{\partial \tilde{y}^{j}}{\partial x^{i}}\).
  • Another participant emphasizes the natural description of coordinates \(x^{i}\) on the tangent bundle but expresses uncertainty about whether \(y^{i}\) are induced coordinates or refer to a selected moving frame.
  • A later reply suggests that the initial poster may not receive an answer but encourages further responses from more knowledgeable participants.

Areas of Agreement / Disagreement

Participants express differing views on the nature of the coordinates and their dependencies, indicating that the discussion remains unresolved regarding the independence of the variables.

Contextual Notes

There are unresolved assumptions about the nature of the coordinates and their relationships, particularly concerning the definitions of induced coordinates versus arbitrary selections.

math6
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The triplet \left ( TM,M,\pi \right ) is a vector bundle called the tangent bundle TM such that M is its manifold basis, \pi : TM \rightarrow M the canonical projection. \left ( x^{i},y^{i} \right ) is a local coordinate system on a map \left ( \pi^{-1}(U),\varphi_{U} \right ).
x^{i} is the system of map coordinates \left ( U,\varphi \right ) of M and y^{i} are as
y= y^{i}\frac{\partial }{\partial x^{i}} , y \in T_{x}M .
Now if we take a new system of coordinates \left ( \tilde{x}^{i}, \tilde{y}^{i} \right )
on a map ( \pi^{-1}(V),\phi _{U} \right ) . \tilde{x}^{i} is the system of map coordinates \left ( V,\psi \right ) of M.
Then after the change of coordinates we have the following results :
( 1) \frac{\partial }{\partial \tilde{x}^{i}} = \frac{\partial x^{k}}{\partial \tilde{x}^{i}}\frac{\partial }{\partial x^{k}} .
(2) \tilde{y}^{j}= \frac{\partial x^{j}}{\partial \tilde{x}^{l}}y^{l}.

My question is this: It is clear from (1) that {x}^{i} depends \tilde{x}^{j} (and vice versa)
also {y}^{i} depends \tilde{y}^{j}. So \tilde{y}^{j} does it depend of {x}^{i} ?
What is the value then of \frac{\partial \tilde{y}^{j}}{\partial x^{i}} ?

In short, I seek the independence of variables \left ( x^{i},y^{i} \right ) and \left ( \tilde{x}^{i}, \tilde{y}^{i} \right ).
 
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Yes, use the features. Now, the whole point is that coordinates x^i in a natural way coordinates on the tangent bundle. And normally this is how the tangent bundle is described. I am not sure from your post whether y^i[/tex] are the induced coordinates in this way, or "any coordinates", for instance referring to some selected "moving frame".
 
The triplet \left ( TM,M,\pi \right ) is a vector bundle called the tangent bundle TM such that M is its manifold basis, \pi : TM \rightarrow M the canonical projection. \left ( x^{i},y^{i} \right ) is a local coordinate system on a map \left ( \pi^{-1}(U),\varphi_{U} \right ).
x^{i} is the system of map coordinates \left ( U,\varphi \right ) of M and y^{i} are as
y= y^{i}\frac{\partial }{\partial x^{i}} , y \in T_{x}M .
Now if we take a new system of coordinates \left ( \tilde{x}^{i}, \tilde{y}^{i} \right )
on a map ( \pi^{-1}(V),\phi _{U} \right ),\tilde{x}^{i}) is the system of map coordinates \left ( V,\psi \right ) of M.
Then after the change of coordinates we have the following results :
(1) \frac{\partial }{\partial \tilde{x}^{i}} = \frac{\partial x^{k}}{\partial \tilde{x}^{i}}\frac{\partial }{\partial x^{k}} .
(2) \tilde{y}^{j}= \frac{\partial x^{j}}{\partial \tilde{x}^{l}}y^{l}.

My question is this: It is clear from (1) that {x}^{i} depends \tilde{x}^{j} (and vice versa)
also {y}^{i} depends \tilde{y}^{j} So \tilde{y}^{j} does it depend of {x}^{i} ?
What is the value then of \frac{\partial \tilde{y}^{j}}{\partial x^{i}} ?

In short, I seek the independence of variables \left ( x^{i},y^{i} \right ) and \left ( \tilde{x}^{i}, \tilde{y}^{i} \right )

Although I don't have an answer to your question, this might help you get more responses by those that are more knowledgeable.

Kevin
 
Last edited:

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