Can B Be Determined from Given A and C in Kronecker Product?

umut_caglar
Messages
7
Reaction score
0
hi everybody

Today I have a question about Kronecker products, If you have a direct answer it is perfect but if not, any kind of paper reference might work as well.

now say I have to matrices A and B in general there is nothing special about them. They are not hermitian or triangular or what ever special.

then I calculate the Kronecker product between them A \otimes B = C

then assume that A and C is given to us and we want to figure out what B is. I know that B is not unique but is there anything that we can say about B? Do you know any algorithm that can give some predictions or guesses for B.

I know one stuff that can approximately decompose C into a A', B' pair. But in this algorithm you do not have any control on A or B.

http://www.mit.edu/~wingated/scripts/krondecomp.m

any idea is welcome, thank you.
 
Physics news on Phys.org
Given ##A## and ##C## makes ##B## unique. The elements of ##C## are pairs ##c_{ijkl}=a_{ij}b_{kl}##. Tensor products are not unique in the sense that ##\lambda A\oplus B = A \oplus \lambda B##. But as you nailed ##A##, there are no scalars ##\lambda \neq 1## which can be swapped. Also, as you have only a dyade, sums don't have any effect either, as there are simply none.
 
I asked online questions about Proposition 2.1.1: The answer I got is the following: I have some questions about the answer I got. When the person answering says: ##1.## Is the map ##\mathfrak{q}\mapsto \mathfrak{q} A _\mathfrak{p}## from ##A\setminus \mathfrak{p}\to A_\mathfrak{p}##? But I don't understand what the author meant for the rest of the sentence in mathematical notation: ##2.## In the next statement where the author says: How is ##A\to...
The following are taken from the two sources, 1) from this online page and the book An Introduction to Module Theory by: Ibrahim Assem, Flavio U. Coelho. In the Abelian Categories chapter in the module theory text on page 157, right after presenting IV.2.21 Definition, the authors states "Image and coimage may or may not exist, but if they do, then they are unique up to isomorphism (because so are kernels and cokernels). Also in the reference url page above, the authors present two...
When decomposing a representation ##\rho## of a finite group ##G## into irreducible representations, we can find the number of times the representation contains a particular irrep ##\rho_0## through the character inner product $$ \langle \chi, \chi_0\rangle = \frac{1}{|G|} \sum_{g\in G} \chi(g) \chi_0(g)^*$$ where ##\chi## and ##\chi_0## are the characters of ##\rho## and ##\rho_0##, respectively. Since all group elements in the same conjugacy class have the same characters, this may be...
Back
Top