Gram Schmidt procedure, trouble finding inner product

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Homework Help Overview

The discussion revolves around the Gram-Schmidt procedure for constructing an orthonormal basis from a given set of basis vectors |x>, |y>, and |z>. The participants are exploring the normalization of these vectors based on specified inner products.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to normalize the vector |y'> after calculating |x'>, but expresses uncertainty about the inner product needed for normalization. They question how to handle the inner product of sums of kets and bras.

Discussion Status

Some participants provide guidance on the proper approach to taking inner products in the context of normalization, emphasizing the importance of using complex conjugates. The original poster acknowledges the feedback and reports progress in their understanding.

Contextual Notes

Participants are working under the constraints of the given inner products and the requirement to express the new basis vectors in terms of the original ones. There is a focus on ensuring mathematical rigor in the normalization process.

Jimmy000
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Homework Statement


Given basis |x>,|y>,|z> such that <x|x> = 2,<y|y> = 2,<z|z> = 3,<x|y> = i, <x|z> = i, and <y|z> = 2. Build an orthonormal basis|x'>,|y'>,|z'>. Each of the new basis vectors should be expressed in terms of the old ones multiplied by coefficients.

Homework Equations



|x'> = |x>/(<x|x>).5 (normalizing the original x ket)

|y'> = |y> - <x'|y> |x'>

The Attempt at a Solution


So far I have worked through that |x'> = (1/2).5|x>
Using this result I have moved through the calculation of |y'> and found it equals

|y> - (i/2) |x'>

I am now trying to normalize this expression, but I am not sure what my inner product on the denominator will look like for this normalization, but my best guess is
<y| - (i/2)<x'|y> - (i/2)|x'>

but that does not look legitimate to me, so I am stuck here.

How do I take the inner product of a bra and and ket, both of which are sums of two kets/bras?
 
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Jimmy000 said:

Homework Statement


Given basis |x>,|y>,|z> such that <x|x> = 2,<y|y> = 2,<z|z> = 3,<x|y> = i, <x|z> = i, and <y|z> = 2. Build an orthonormal basis|x'>,|y'>,|z'>. Each of the new basis vectors should be expressed in terms of the old ones multiplied by coefficients.

Homework Equations



|x'> = |x>/(<x|x>).5 (normalizing the original x ket)

|y'> = |y> - <x'|y> |x'>

The Attempt at a Solution


So far I have worked through that |x'> = (1/2).5|x>
Using this result I have moved through the calculation of |y'> and found it equals

|y> - (i/2) |x'>

I am now trying to normalize this expression, but I am not sure what my inner product on the denominator will look like for this normalization, but my best guess is
<y| - (i/2)<x'|y> - (i/2)|x'>

but that does not look legitimate to me, so I am stuck here.

How do I take the inner product of a bra and and ket, both of which are sums of two kets/bras?
Use parentheses. If you had a = b + c, you wouldn't say ##a\times a = b + c\times b + c##, would you? That's effectively what you're doing right now, so it's not surprising it doesn't look right to you.
 
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In the "bra"-"ket" formalisim the bra is the complex conjugate of the ket. In your normalizing denominator you must take the inner-product of the vector with its complex conjugate.
 
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Thanks a million! I always mix up how kets and bras correlate to normal vector notation. I worked it through being mindful of parentheses and I got a much more logical answer :biggrin:
 

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