Multitude of Quantum Mechanics questions

Click For Summary
SUMMARY

This discussion focuses on key concepts in quantum mechanics, specifically the Hamiltonian, the time-independent Schrödinger equation, and the completeness of solutions in an infinite potential well. The Hamiltonian represents the total spectrum of energy values, with measured values being eigenvalues. For the time-independent Schrödinger equation, normalizable solutions do not exist for cases where energy E is less than potential V. Additionally, while solutions in an infinite well form a complete set, they do not encompass all mathematical functions but rather functions in the space L2(0,1).

PREREQUISITES
  • Understanding of quantum mechanics principles
  • Familiarity with Hamiltonian mechanics
  • Knowledge of the time-independent Schrödinger equation
  • Concept of function spaces, specifically L2 spaces
NEXT STEPS
  • Study the properties of the Hamiltonian in quantum mechanics
  • Explore the implications of the time-independent Schrödinger equation in various potentials
  • Investigate the concept of completeness in function spaces
  • Learn about Fourier Series and their applications in quantum mechanics
USEFUL FOR

Students and professionals in physics, particularly those studying quantum mechanics, as well as educators and researchers looking to deepen their understanding of quantum systems and mathematical frameworks.

Master J
Messages
219
Reaction score
0
I am studying Quantum mechanics at the moment, and so naturally a few questions arise!
So I will post them in this thread.

Cheers for any input, I really appreciate all the help that I get! :smile:

First off:

1. My picture of the Hamiltonian is that it is the total spectrum of possible energy values for a system, but to know what energy state it is actually in, one must perform a measurement on the system.This measured valued would then be an eigenvalue of the Hamiltonian. Is this correct?

2. For the time independent Schrödinger equation in one - dimension, can one find a normalizable solution for any x in the case the E<V (V is the potential)?? I know the graph of such a solution would look like a parabola ( and a parabola heading towards negative infinity also), and so I would presume no, but why not exactly?

3. The solutions to the time indep Schrödinger equation in an infinite well form a complete set. Does this mean ANY function in mathematics? This would in fact be the definition of a Fourier Series in this case...I find that odd and somewhat hard to believe!
 
Physics news on Phys.org
Master J said:
1. My picture of the Hamiltonian is that it is the total spectrum of possible energy values for a system, but to know what energy state it is actually in, one must perform a measurement on the system.This measured valued would then be an eigenvalue of the Hamiltonian. Is this correct?
I would say that the set of all eigenvalues of the Hamiltonian are the total spectrum of possible energy values for a system.

Master J said:
2. For the time independent Schrödinger equation in one - dimension, can one find a normalizable solution for any x in the case the E<V (V is the potential)?? I know the graph of such a solution would look like a parabola ( and a parabola heading towards negative infinity also), and so I would presume no, but why not exactly?
What kind of potential are you thinking of here? Are you thinking of a finite well a harmonic oscillator or what?

Master J said:
3. The solutions to the time indep Schrödinger equation in an infinite well form a complete set. Does this mean ANY function in mathematics? This would in fact be the definition of a Fourier Series in this case...I find that odd and somewhat hard to believe!
In general it does not mean any function in mathematics. It means any vector in some space of functions, for example L2(0,1). Typically this could be described as any "well behaved" function in the well.
 

Similar threads

  • · Replies 5 ·
Replies
5
Views
1K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 22 ·
Replies
22
Views
3K
  • · Replies 44 ·
2
Replies
44
Views
6K
  • · Replies 27 ·
Replies
27
Views
3K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 12 ·
Replies
12
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K