Simple Dirac Notation Problem: Dot Product of Two Vectors

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SUMMARY

The discussion centers on the dot product of two vectors in Dirac notation, specifically examining the expression and its equivalence to + . Participants clarify that the star (complex conjugate) should not be placed outside the bra, and emphasize that the vector |c> is not normalized. The conversation highlights the importance of understanding state vectors and wavefunctions in quantum mechanics, particularly for beginners learning Dirac notation.

PREREQUISITES
  • Understanding of Dirac notation and its components, such as bras and kets.
  • Familiarity with complex conjugates in quantum mechanics.
  • Basic knowledge of state vectors and wavefunctions.
  • Awareness of normalization in quantum states.
NEXT STEPS
  • Study the properties of complex conjugates in quantum mechanics.
  • Learn about normalization of quantum states and its significance.
  • Explore the mathematical foundations of Dirac notation.
  • Investigate the implications of state vectors in quantum mechanics.
USEFUL FOR

Students of quantum mechanics, particularly those new to Dirac notation, as well as educators and anyone seeking to clarify the mathematical principles underlying quantum states and their representations.

Jalo
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Homework Statement



Imagine you have two vectors |a> and |b> such that:
|c> = |a> + |b>

Now imagine you want the dot product:

<c|a>

Is that the same as:

<c|a> = [ <a|*+<b|* ] |a> = <a*|a> + <b*|a>

where * represents the complex conjugate of the vector?


Homework Equations





The Attempt at a Solution

~

Thanks in advance for any answer.

Daniel
 
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You'd not normally put the star outside the bra like that.
if a is a state then |a> is the state vector corresponding to wavefunction Ya ... we may sometimes write |Ya> when you are starting out.

##<\psi_a|\psi>= \int \psi_a^\star \psi##

(I'm hoping someone else can do a better job of this explanation. :/ )
BTW: you know your vector |c> is not normalized right?
 
Simon Bridge said:
You'd not normally put the star outside the bra like that.
if a is a state then |a> is the state vector corresponding to wavefunction Ya ... we may sometimes write |Ya> when you are starting out.

##<\psi_a|\psi>= \int \psi_a^\star \psi##

(I'm hoping someone else can do a better job of this explanation. :/ )
BTW: you know your vector |c> is not normalized right?

Yes, I'm aware that |c> is not normalized, but in this case it doesn't matter. I'm just learning the math behind Dirac's notation. I am not yet working with state vectors or anything of that kind.
Thanks for your answer!
 

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