Download greek-index.mw

I am trying to do matrix multiplication with Dirac gamma matrices, but am getting a recursion error. 

the final input line, which is causing the error, doesn't seem to be inserted, but it is:

Library:-PerformMatrixOperations((mt . (Dgamma[2])) . m)

can anybody tell me what i'm doing wrong? i don't understand why 

Dgamma[2] . m 

works but 

mw . Dgamma[2] . m 

gets the recursion error. 

then i saw something that made me think i needed to use 'matrix', instead of 'Matrix'. so i tried that(gamult2) - now the 2nd multiply works, and the first fails.

any help greatly appreciated!

thanks,

larry

Download gammult.mw

gammult2.mw

hi,

I want to setup quantum mechanical angular momentum operators and kets such that i can do something like:

Lz[2] . Ket(??, j, m) -> m hbar        (instead of getting m as eigenvalue)

L^2[1] . Ket(??, j, m) -> j (j+1) hbar^2           (instead of getting j)

where L and Lz are quantum operators. 

maybe if i knew how to do 

QuantumOp . Ket{QuantumOp, j) -> j (j+1)

i could do it with explicit tensor products of Kets - one for j, one for m?

can somebody give me an idea of how to do this, or point me at an example?

many thanks,

larry

is there a way to have output left justified, instead of centered?

in other words, i want this:

4-1

3

not the normal

4-1

                                                                 3

thanks

please see maple attachment below.

btw, what i'm really trying to do is represent spin 1/2 states, along with the usual spin operators, and be able to take tensor products of the spin states. any hints on how to do that would be greatly appreciated. 

btw, the physics package is amazing! 

thanks, 

larry

bug.mw