Please check my work on inner product operation

iScience
Messages
466
Reaction score
5
i realize this is a linear algebra question, but the bra-ket notation is still a little confusing to me so i posted it in this section.


|e>=(1+i,1,i) (n-tuple representation, where i's are the imaginaries)

so the norm of this would then be the following?

||e||=$$\sqrt{<e|e>}$$=$$\sqrt{(1+i,1,i)\cdot(1+i,1,i)}$$=$$\sqrt{(1+2i+i^2)+1+i^2}$$=$$\sqrt{2i}$$
 
Physics news on Phys.org
iScience said:
i realize this is a linear algebra question, but the bra-ket notation is still a little confusing to me so i posted it in this section.


|e>=(1+i,1,i) (n-tuple representation, where i's are the imaginaries)

so the norm of this would then be the following?

||e||=$$\sqrt{<e|e>}$$=$$\sqrt{(1+i,1,i)\cdot(1+i,1,i)}$$=$$\sqrt{(1+2i+i^2)+1+i^2}$$=$$\sqrt{2i}$$

No, it's not right. If |e>=(1+i,1,i) then <e| is the hermitian conjugate vector. You forgot the complex conjugation. <e|e> should be a real number.
 
Thread 'Need help understanding this figure on energy levels'
This figure is from "Introduction to Quantum Mechanics" by Griffiths (3rd edition). It is available to download. It is from page 142. I am hoping the usual people on this site will give me a hand understanding what is going on in the figure. After the equation (4.50) it says "It is customary to introduce the principal quantum number, ##n##, which simply orders the allowed energies, starting with 1 for the ground state. (see the figure)" I still don't understand the figure :( Here is...
Thread 'Understanding how to "tack on" the time wiggle factor'
The last problem I posted on QM made it into advanced homework help, that is why I am putting it here. I am sorry for any hassle imposed on the moderators by myself. Part (a) is quite easy. We get $$\sigma_1 = 2\lambda, \mathbf{v}_1 = \begin{pmatrix} 0 \\ 0 \\ 1 \end{pmatrix} \sigma_2 = \lambda, \mathbf{v}_2 = \begin{pmatrix} 1/\sqrt{2} \\ 1/\sqrt{2} \\ 0 \end{pmatrix} \sigma_3 = -\lambda, \mathbf{v}_3 = \begin{pmatrix} 1/\sqrt{2} \\ -1/\sqrt{2} \\ 0 \end{pmatrix} $$ There are two ways...
Back
Top