Differential Form - Notation Help

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Discussion Overview

The discussion revolves around the notation used in differential forms, particularly in the context of Holonomic constraints. Participants seek clarification on the mathematical expressions and their implications within this framework.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification

Main Points Raised

  • Geoff requests an explanation of the notation related to differential forms as presented on a Wikipedia page, specifically in the context of Holonomic constraints.
  • One participant provides equations related to the constraints, indicating that Cij represents the partial derivative of the i-th constraint with respect to the j-th coordinate, and Ci represents the partial derivative with respect to time.
  • Another participant interprets the notation, suggesting that dhqs and dt can be seen as small increments in the coordinates and time, and defines a differential 1-form as a linear function on tangent vectors that varies smoothly across tangent spaces.
  • A participant expresses confusion regarding the presence of lower indices on the coordinate differentials and notes an expectation for an equal number of indices on the variable c.

Areas of Agreement / Disagreement

The discussion reflects a lack of consensus, with participants expressing different levels of understanding and raising questions about the notation without arriving at a unified interpretation.

Contextual Notes

There are unresolved questions regarding the notation, particularly concerning the use of indices and the implications of the definitions provided.

Mistake Not...
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Hi there,

I was reading up on Holonomic constraints and came across this equation on the Wikipedia page:

fa14f9c440da57168334ebf30c88cf09.png


The page says it is a differential form. Can anyone explain the notation for me or provide a link or two to documents or pages which explain this notation?

Thank you very much,
Geoff
 
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Cij = ∂fi/∂qj
and
Ci = ∂fi/∂t where fi is the i th constraint. and qj is the j th coordinate.
 
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Mistake Not... said:
Hi there,

I was reading up on Holonomic constraints and came across this equation on the Wikipedia page:

fa14f9c440da57168334ebf30c88cf09.png


The page says it is a differential form. Can anyone explain the notation for me or provide a link or two to documents or pages which explain this notation?

Thank you very much,
Geoff

You can interpret the dhqs and dt as small increments in the q's and in t.

Formally a differential 1 form is a linear function on tangent vectors that varies smoothly from one tangent space to the next. .
 
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I'm quite confused.

fa14f9c440da57168334ebf30c88cf09.png


Why are there lower indices on the ##q^i##coordinate differentials?

I would also expect to see an equal number of indeces on ##c##.
 
Last edited:

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