How to Write M(x,x') in Dirac Notation?

In summary: It is the derivative of the function x with respect to x. So when you say "I think m(x) = <x|M> .. ", what you are saying is that m(x) is the derivative of x with respect to M.
  • #1
raj2004
7
0
Hey guys,
I am having difficulty interpreting M(x,x') into dirac notation. How do i write M(x,x') in dirac notation? The actual problem is to write the following in dirac notation:

int { int { m(x)* M(x,x') g(x') } dx} dx'

I would appreciate your help.
 
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  • #2

Homework Statement


Hey guys,
I am having difficulty interpreting M(x,x') into dirac notation. How do i write M(x,x') in dirac notation? The actual problem is to write the following in dirac notation:
I would appreciate your help.


Homework Equations


int { int { m(x)* M(x,x') g(x') } dx} dx'





The Attempt at a Solution


i tried to use M(x,x') = m(x) m(x'). would that be appropriate?
 
  • #3
could anyone help me on this ?
 
  • #4
what is what in
int { int { m(x)* M(x,x') g(x') } dx} dx'
?
 
  • #5
int means integration
 
  • #6
and what about m , M, g? are the states, operators .. what is what?
 
  • #7
Consider the inner product [itex]\langle m | M | g \rangle[/itex] and write it out in the position basis (hint, insert the completeness relation twice, once at each vertical bar).
 
  • #8
For your attempt at solution, I don't know what M and m are supposed to be, but if they are what I think they are (M is some sort of propagator and m is a state) then I don't think you can write this.
 
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  • #9
I think m(x) = <x|M> and m(x)* = <M|x>. But i don't know what to write for M(x,x') in dirac notation. Here x and x' are two different bases. Also, g(x') = <x'|g>.
 
  • #10
CompuChip said:
Consider the inner product [itex]\langle m | M | g \rangle[/itex] and write it out in the position basis (hint, insert the completeness relation twice, once at each vertical bar).

Have you tried that already?
 
  • #11
Ok, now i tried it. Following what you said, I found above integral equals to <m|M|g>. But i don't understand what you mean by M(x,x') is propagator? In dirac notation does M(x,x') equal to <x|M|x'> . It works out fine if i make that assumption.
 
  • #12
What does your original integral equal? And what do you mean by "I think m(x) = <x|M> .. " ? You don't know?
 
  • #13
No. I was not sure about that statement. But now it's clear. m(x) = <x|m> , not <x|M>. Thanks for your help guys. I get the answer <m|M|g>. But i still don't understand why M(x,x') = <x|M|x'>?
 
  • #14
OK, let me put it this way: do you know what [itex]\int \mathrm{d}x |x\rangle\langle x|[/itex] is?
 

FAQ: How to Write M(x,x') in Dirac Notation?

1. What is Dirac notation?

Dirac notation, also known as bra-ket notation, is a mathematical notation used in quantum mechanics to represent the state of a quantum system. It was developed by physicist Paul Dirac in the early 20th century.

2. How is M(x,x') written in Dirac notation?

In Dirac notation, M(x,x') is written as <x|M|x'>, where |x> and |x'> are the bra and ket vectors representing the initial and final states of the system, respectively. The operator M represents the transformation of the state from |x> to |x'>.

3. What is the purpose of writing M(x,x') in Dirac notation?

Writing M(x,x') in Dirac notation allows for a more concise and elegant representation of the transformation of a quantum system. It also allows for easy manipulation and calculation of various quantum mechanical quantities.

4. How is M(x,x') interpreted in Dirac notation?

M(x,x') in Dirac notation represents the inner product of the bra vector |x> with the ket vector |x'>. This inner product is also known as the transition amplitude, which gives the probability amplitude for the system to transition from state |x> to state |x'>.

5. Are there any other notations that can be used to represent M(x,x')?

Yes, besides Dirac notation, M(x,x') can also be represented using matrix notation or wavefunction notation. However, Dirac notation is the most commonly used notation in quantum mechanics due to its simplicity and usefulness.

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