Multidimensional cross product vector

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Discussion Overview

The discussion revolves around the computation of the cross product vector in dimensions greater than three, exploring theoretical frameworks and potential resources for understanding this concept. Participants express interest in both the mathematical definitions and practical applications.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants inquire about the formulas for computing the cross product in more than three dimensions, noting that traditional linear algebra textbooks primarily focus on the 3D case.
  • One participant suggests looking into the wedge product and mentions Grassmann's framework of "Geometric Calculus," which includes inner and outer products.
  • Another participant points out that the cross product is traditionally defined only in \(\mathbb{R}^3\) and references Wikipedia for generalizations of the cross product.
  • A participant explains that to have a unique cross product vector in n-dimensional space, one must start with n-1 vectors, indicating that in 4D space, the cross product of three vectors can be defined.
  • There is mention of David Bachman's book as a resource that provides a geometric treatment of the subject.
  • One participant shares a link to an external resource that offers explanations and an interactive program related to the cross product.

Areas of Agreement / Disagreement

Participants express differing views on the definition and applicability of the cross product in higher dimensions, with no consensus reached on a singular method or formula for computation.

Contextual Notes

Limitations include the lack of consensus on definitions and the dependence on specific mathematical frameworks, as well as the unresolved nature of how to generalize the cross product beyond three dimensions.

Olaf
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Does anyone knows how to compute cross product vector of more than 3 dimensions? It seems all the linear algebra textbooks only discuss 3D cross product vector. What are the formulas?
 
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Olaf said:
Does anyone knows how to compute cross product vector of more than 3 dimensions? It seems all the linear algebra textbooks only discuss 3D cross product vector. What are the formulas?

Look into the wedge product.

If you are interested in the origins read about Grassmann's framework of "Geometric Calculus" and further developments including that by Clifford.

Grassmann breaks geometric calculus into inner and outer products.

You also might want to look at linear algebra (a good graduate book), and look into books that describe tensor algebra.
 
Thanks but do you know any info in the internet? I don't have those books you mentioned.
 
a cross product of some vectors is supposed to be perpendiculkar to all of them and have lnegth equal to the volume they span, and be right hand oriented.

So if you want there to be only one such vector, you need to start with a product of n-1

vectors in n space. that's why you can multiply 2 of them, only in 3 space. in 4 space the cross product of three vectors makes sense.

But if you are willing to have a product which is more than one vector, maybe some kind of block, you can do it with fewer.

david bachman's book gives a nice treatment of the geometry of this subject.
 

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