Help with proof of eq. 2.64 of Intro. to Quantum Mechanics

In summary, the conversation discusses the proof for equation 2.64 in the book "Introduction to Quantum Mechanics, 2e" by Griffith on page 47. The proof is not very elaborate and the person is requesting a more step-by-step explanation. They also ask if the roots of the Hamiltonian, a+ and a-, are real and if the operator ${d \over dx}$ picks up a minus sign under hermitian conjugation. The response explains that the Hamiltonian roots are not real and provides an explanation for the behavior of the operator under hermitian conjugation.
  • #1
SherLOCKed
13
1
I am self studying the Book- Introduction to Quantum Mechanics , 2e. Griffith. Page 47.
While the book has given a proof for eq. 2.64 but its not very ellaborate
Integral(infinity,-infinity) [f*(a±g(x)).dx] = Integral(infinity,-infinity) [(a±f)* g(x).dx] . It would be great help if somebody could provide me a more step by step proof of the same.
Where a+ and a- are roots of Hamiltonian of harmonic oscillator problem.
 
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  • #2
Are a+ and a- real? If so it would be justified.
 
  • #3
The operator

$${d \over dx}$$ picks up a minus sign under hermitian conjugation when the hilbert space is that of functions that vanish fast enough at infinity. The reason why that's true is because:

$$\int f {d g \over dx} = 0 - \int g {df \over dx} dx$$

This implies that when you take the hermitian conjugate of the $\hat{a}_+$ operator, just replace ${d \over dx}$ by $-{d \over dx}$ which gives the $\hat{a}_-$ operator
 
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  • #4
SherLOCKed said:
Where a+ and a- are roots of Hamiltonian of harmonic oscillator
Be careful there: they are not! There is a constant ##\hbar\omega## difference !
 

Related to Help with proof of eq. 2.64 of Intro. to Quantum Mechanics

1. What is equation 2.64 of Intro. to Quantum Mechanics?

Equation 2.64 of Intro. to Quantum Mechanics is a mathematical representation of the time evolution of a quantum system. It is also known as the Schrodinger equation.

2. Why is it important to have a proof of equation 2.64?

Having a proof of equation 2.64 is important because it allows us to understand the fundamental principles of quantum mechanics and how particles behave at the quantum level. It also serves as a basis for further advancements and applications in the field.

3. Who first discovered equation 2.64?

Equation 2.64 was first discovered by Austrian physicist Erwin Schrodinger in 1925 as a result of his work on wave mechanics.

4. How is equation 2.64 derived?

Equation 2.64 is derived using mathematical techniques such as complex analysis and linear algebra. It is based on the principles of quantum mechanics, including the wave function and the Hamiltonian operator.

5. What are some applications of equation 2.64?

Equation 2.64 has many applications in various fields, including quantum computing, quantum chemistry, and quantum cryptography. It is also used in the development of new technologies and in understanding the behavior of particles at the quantum level.

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