Vector calculus identity format question

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Discussion Overview

The discussion revolves around the identity involving the Laplacian operator applied to a vector field and its magnitude. Participants explore the relationship between the vector Laplacian and the scalar Laplacian, as well as potential formulations of the identity.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant recalls an identity involving the Laplacian of a vector and its magnitude but cannot remember the exact form.
  • Another participant provides links to external resources for the vector Laplacian and scalar Laplacian, suggesting these may contain relevant information.
  • A different participant suggests a method to express the vector in terms of its magnitude and a unit vector, indicating that deriving the Laplacian in this form may not yield a simple result.
  • Another participant references a vector identity related to the vector Laplacian, providing a link to an external source for further details.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the specific identity in question, and multiple approaches and resources are presented without resolution.

Contextual Notes

Limitations include the lack of a clear definition of the identity being sought and the potential complexity of the derivations suggested by participants.

Who May Find This Useful

Readers interested in vector calculus, particularly those exploring identities involving the Laplacian operator in vector fields.

kent davidge
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I know there is an identity involving the Laplacian that is like ##\nabla^2 \vec A = \nabla^2 A## where ##\vec A## is a vector and ##A## is its magnitude, but can't remember the correct form. Does anyone knows it?
 
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If you were so inclined you could set ##\vec{A}=|\vec{A}|\hat{n}##, then churn out how the Laplacian looks in terms of various derivatives of ##|\vec{A}|## and ##\hat{n}##. I don't think you will get anything pretty.
 
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There's a vector identity with the vector laplacian here:

https://mathworld.wolfram.com/VectorLaplacian.html

NumberedEquation1.gif
 
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