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What is a 4-tensor ?

  1. Sep 16, 2003 #1

    pmb

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    what is a "4-tensor"?

    Has anyone here thought at one time that the term "4-tensor" (aka "four tensor") was refering to a 4th rank tensor? Somone made this mistake and I'm, of course, curious as to how wide spread this misconception is.

    Thanks

    Pete
     
  2. jcsd
  3. Sep 16, 2003 #2

    chroot

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    Staff Emeritus
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    I don't know that I've ever made the mistake, or even used the term "4-tensor." Is a 4-tensor a tensor whose indices range over four values?

    - Warren
     
  4. Sep 17, 2003 #3

    pmb

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    Yes. It's a use which is similar to that of "4-vector" in that the tensor is defined on a 4d manifold. For examples of usage see

    For online notes for details see --
    www.wikipedia.org/wiki/Maxwell's_equations
    farside.ph.utexas.edu/~rfitzp/teaching/jk1/lectures/node10.html
    farside.ph.utexas.edu/~rfitzp/teaching/jk1/lectures/node13.html
    farside.ph.utexas.edu/~rfitzp/teaching/jk1/lectures/node23.html
    farside.ph.utexas.edu/teaching/jk1/relativity.pdf
    cosmos.astroscu.unam.mx/~sergio/phdthesis/phdlatex2html/node17.html
    www.hep.princeton.edu/~mcdonald/examples/fieldmomentum.pdf



    Pete
     
  5. Sep 17, 2003 #4

    pmb

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    There are some interesting comments inThorne and Blanchard's new text. From Chapter 1: Physics in Flat Spacetime: Geometric
    Viewpoint
    - page 38-39
    (http://www.pma.caltech.edu/Courses/ph136/yr2002/chap01/0201.2.pdf)
    If anyone knows of another source which discusses the E and B fields as 4-vectors can you please let me know - references etc.?

    Thanks

    Pete
     
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