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Re: Contraction of Tensors in Mathematica

• To: mathgroup at smc.vnet.net
• Subject: [mg112541] Re: Contraction of Tensors in Mathematica
• From: Leonid Shifrin <lshifr at gmail.com>
• Date: Sun, 19 Sep 2010 05:38:39 -0400 (EDT)

Sam,

You may want to take a look at this thread:

http://groups.google.com/group/comp.soft-sys.math.mathematica/browse_thread/thread/7f0195213d9d50e0

<http://groups.google.com/group/comp.soft-sys.math.mathematica/browse_thread/thread/7f0195213d9d50e0>
Regards,
Leonid



On Sat, Sep 18, 2010 at 3:25 PM, Sam Takoy <sam.takoy at yahoo.com> wrote:

> Hi,
>
> I this message I will suppress the covariant/contravariant nature of
> tensors.
>
> Suppose I have two tensors A_ijkl and B_rstu (denoted by a and b in
> Mathematica). Each tensor is presented for a 4-deep list. Now, I want to
> form a new tensor:
>
> C_ijklrstu = A_ijkl*B_rstu
>
> and I want C to be represented by an 8-deep list. I've gathered is that
> what I need to do is
>
> c = Outer[Times, a, b];
>
> Great!
>
> Now supposed I want to do some contraction to define a new tensor
>
> D_jklrsu = C_ijklrsiu?
>
>
> How do I do that?
>
> Many thanks in advance!
>
> Sam
>