Verifying that a tensor is isotropic

In summary, the conversation discusses verifying the isotropy of a fourth-rank tensor assuming cartesian coordinates. The definition of isotropic is mentioned, and the individual is unsure of how to begin the problem or find a mathematical definition. They have figured out that the tensor needs to be rotated, but are unsure of how to proceed with the transformation.
  • #1
evlyn
15
0
I'm supposed to verify that this fourth-rank tensor is isotropic assuming cartesian coordinates: [A]_{}[/ijkl]=[δ]_{}[/kl][δ_{}[/kl]

from what I gathered being isotropic means that it stays the same no matter what the rotation is

I have no clue how to even start this problem or what I am looking at.
 
Physics news on Phys.org
  • #2
I recommend that, instead of saying what you "gather" isotropic means, you write out the specific definition. You use the precise words of definitions in mathematics proofs.
 
  • #3
I'm not even sure how to go about doing that. I am taking math methods but have been out of school for a while and just trying to relearn things and I never took a proof class before. My book does not give any definition other than the one in English but there is no math that I can find that has the definition. Is there someplace I could go to find the definition.
 
  • #4
So I figured out that I need to rotate the tensor and from there show that it is the same in the new rotation. So if I have A_ijkl=(δ_ij)(δ_kl) In order to transform it I'm not really sure how to proceed.
 
Last edited:

FAQ: Verifying that a tensor is isotropic

What is an isotropic tensor?

An isotropic tensor is a mathematical object that has the same value in all directions and orientations. It is invariant under rotations and has no preferred direction.

How do you verify that a tensor is isotropic?

To verify that a tensor is isotropic, you can perform a rotation test. This involves rotating the tensor in different directions and checking if its values remain the same. If the values are unchanged, the tensor is isotropic.

What are the properties of an isotropic tensor?

Some key properties of an isotropic tensor include being invariant under rotations, having equal values in all directions, and having no preferred direction. Additionally, an isotropic tensor is symmetric, meaning its components are the same when they are swapped.

Can a tensor be both isotropic and anisotropic?

No, a tensor cannot be both isotropic and anisotropic. These are two opposite properties, with isotropic meaning no preferred direction and anisotropic meaning having a preferred direction. However, a tensor can have both isotropic and anisotropic components.

How is isotropy related to symmetry in tensors?

Isotropy and symmetry are closely related in tensors. An isotropic tensor is symmetric, meaning its components are the same when they are swapped. However, a symmetric tensor may not necessarily be isotropic, as it may have a preferred direction.

Similar threads

Replies
2
Views
3K
Replies
8
Views
2K
Replies
1
Views
1K
Replies
12
Views
2K
Replies
40
Views
2K
Back
Top