K41
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What is an eigenframe?
andrewkirk said:I've never heard of an Eigenframe and neither, apparently, has Google or DuckDuckGo.
However, there's a fairly natural guess we can make. If a linear operator L on a n-dimensional vector space V is non-degenerate, it will have n orthonormal eigenvectors. These form a nice orthonormal basis for V, and bases can be called 'frames'.
If we are concerned with a differentiable manifold rather than just a single vector space then a (1 1) tensor field T on the manifold can be interpreted as a field of linear operators on the tangent bundle. There will be a unique coordinate frame field whose coordinate directions at any point are those of the eigenvectors of the tensor (qua linear operator) at that point. It would make sense to call that coordinate frame field an 'eigenframe' pf the tensor field T.
fresh_42 said:I've found a few occurrences, however no definition. Maybe you could read more out of its applications than I can.
Density matrices:
https://books.google.de/books?id=o0...l5DFoQ6AEIOTAG#v=onepage&q=eigenframe&f=false
Spin:
http://easyspin.org/documentation/hamiltonian.html
https://en.wikipedia.org/wiki/Axiality_and_rhombicity
djpailo said:I don't understand any of this.
The Bill said:If you don't understand "any of this," which includes eigenvectors, then you haven't studied linear algebra enough to have the prerequisites for tensor analysis.
Also, after you learn linear algebra, you might want to study a more general introductory fluid mechanics text before going back to this one which specializes in turbulence.