Ask Your Question

Tensor Product of Two Matrices coming from Algebra Representations

asked 2011-05-03 04:06:56 -0600

ChrisBerg gravatar image

updated 2012-08-03 17:18:20 -0600

vdelecroix gravatar image

Is there a command in sage to compute the tensor product of two Matrices coming from Algebra representations? In groups, x(v tensor w) = xv tensor xw, and the sage command Matrix1.tensor_product(Matrix2) appears to give the matrix corresponding to this. But in an algebra x(v tensor w) = xv tensor w + v tensor xw. How can I compute the corresponding matrix here?

edit retag flag offensive close merge delete


What you need is perhaps "tensor sum", "Kronecker sum".

gundamlh gravatar imagegundamlh ( 2013-11-12 22:51:06 -0600 )edit

1 answer

Sort by ยป oldest newest most voted

answered 2012-08-03 16:50:26 -0600

vdelecroix gravatar image


If M1 is your first matrix (of dimension n1) and M2 is your second matrix (of dimension n2), then the answer should be:

M1.tensor_product(identity_matrix(n2)) + 


edit flag offensive delete link more


M1 "tensor_sum" M2 = eye(n2) "tensor_product" M1 + eye(n1) "tensor_product" M2 .. the tensor product operation is not commutative, I guess. Hence, identity_matrix(n2).tensor_product(M1) + M2.tensor_product(identity_matrix(n1)) , or?

gundamlh gravatar imagegundamlh ( 2013-11-12 22:54:20 -0600 )edit

but this command is too long.. we have to write a my_function or the function "tensor_sum" is already implemented in some packages, such as maxima, Scipy ....

gundamlh gravatar imagegundamlh ( 2013-11-12 22:57:16 -0600 )edit

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

Question Tools

1 follower


Asked: 2011-05-03 04:06:56 -0600

Seen: 2,517 times

Last updated: Aug 03 '12