Valence Tensor of "DVu/Du" Acting on Vector: Analyzing 1 to 1

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Discussion Overview

The discussion revolves around the properties of the covariant derivative and its application to vectors, specifically analyzing the expression for the covariant derivative of a vector and its implications for tensor valence. Participants explore the transformation properties of the resulting tensors and clarify the distinction between contravariant and covariant forms.

Discussion Character

  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant presents the expression for the covariant derivative of a vector and questions whether it correctly transforms from a tensor of valence (1,0) to (1,1).
  • Another participant asserts that the covariant derivative, when contracted with a vector, results in a (1,0) tensor.
  • A subsequent reply seeks clarification on whether the resulting tensor is contravariant rather than covariant, suggesting a potential error in the textbook.
  • Another participant confirms that the resulting tensor is indeed contravariant and suggests verifying this through transformation properties.

Areas of Agreement / Disagreement

Participants express differing views on the transformation properties of the covariant derivative and its resulting tensor forms, indicating that the discussion remains unresolved regarding the textbook's characterization.

Contextual Notes

There are references to specific transformation properties and potential typographical errors in the textbook, but these points remain unverified within the discussion.

binbagsss
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Acting upon a vector say,
so it is defined as:
##\frac{d}{d\lambda}V^{u}+\Gamma^{u}_{op}\frac{dx^{o}}{d\lambda}V^{p}=\frac{DV^{u}}{D\lambda}##

And this can also be written in terms of the covariant derivative, ##\bigtriangledown_{k}## by ##\frac{DV^{u}}{D\lambda}=\frac{d x^{k}}{d \lambda} \bigtriangledown_{k}V^{u}## [1]

So I know that the covariant derivaite takes a tensor of valance ##(p,q)## to ##(p,q+1)##

So using this and the fact that the RHS of [1] has a vector multiplied by a covariant derivative acting upon a vector I would conclude that it takes a ##(1,0)## to a ##(1,1)##. Is this correct?

However my textbook states '##\frac{DV^{a}}{Du}## transforms as a covariant vector, which I don't see,

Thanks.
 
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##\nabla_k V^\mu## is a type (1,1) tensor, but in ##DV^\mu/D\lambda## it is contracted with the vector ##\dot x^k## and therefore becomes a (1,0) tensor.
 
Orodruin said:
therefore becomes a (1,0) tensor.

Ahh I see thanks. And this is a contravariant not a covariant though? And typo in the book?
 
Last edited:
Yes, it is contravariant. You can check this by checking the transformation properties.
 

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