TransWikia.com

Is the determinant a tensor?

Mathematics Asked on December 1, 2021

I was reading Schutz’s book on General Relativity. In it, he says that a(n) $M choose N$ tensor is a linear function of $M$ one-forms and $N$ vectors into the real numbers.

So does that mean the determinant of an $n times n$ matrix is a $0 choose n$ tensor because it is a function that maps the $n$ column vectors of the matrix to a real number (the value of the determinant)?

But then, the determinant also maps the $n$ column vectors of the matrix to the same real number (the value of the determinant).

So would the tensor representation of the determinant be different if you choose the map for the column vectors than the map for the row vectors?

One Answer

Yes, in fact the determinant $det:(mathbb R^n)^nto mathbb R$ is (up to constant multiple) the only alternating $n$-multilinear map (i.e. alternating $n$-covariant tensor). See for instance this question for a proof of this fact.

Answered by Maximilian Janisch on December 1, 2021

Add your own answers!

Ask a Question

Get help from others!

© 2024 TransWikia.com. All rights reserved. Sites we Love: PCI Database, UKBizDB, Menu Kuliner, Sharing RPP