Quantum Harmonic Oscillator Differential Equation help

Click For Summary
SUMMARY

The forum discussion focuses on solving the quantum harmonic oscillator differential equation given by ψ'' + (2ε - y²)ψ = 0. The solution for large y is derived as ψ = Ay^m e^{±y²/2}, with the positive exponential term excluded due to its absence in the physical Hilbert space. The discussion highlights that the solutions to this ordinary differential equation (ODE) are expressed in terms of Modified Bessel functions or Parabolic Cylinder functions, and recommends using the Frobenius method for series expansion to solve the equation.

PREREQUISITES
  • Understanding of quantum mechanics principles, particularly the harmonic oscillator model.
  • Familiarity with differential equations, specifically ordinary differential equations (ODEs).
  • Knowledge of special functions, including Modified Bessel functions and Parabolic Cylinder functions.
  • Proficiency in series expansion techniques, particularly the Frobenius method.
NEXT STEPS
  • Study the Frobenius method for solving ordinary differential equations.
  • Explore the properties and applications of Modified Bessel functions.
  • Learn about Parabolic Cylinder functions and their role in quantum mechanics.
  • Investigate the physical implications of solutions in the context of quantum harmonic oscillators.
USEFUL FOR

Students and researchers in quantum mechanics, mathematicians focusing on differential equations, and physicists interested in the quantum harmonic oscillator and its mathematical solutions.

cybla
Messages
16
Reaction score
0
Hi, so i am looking at the quantization of the harmonic oscillator and i have the following equation...

ψ''+ (2ε-y^{2})ψ=0

I am letting y\rightarrow \infty to get...

ψ''- y^{2}ψ=0

It says the solution to this equation in the same limit is...

ψ= Ay^{m}e^{\pm y^{2}/2}

The positive possibility in the exponential is ignored since it is not in the physical Hilbert space. My question is how did they solve this differential equation? I have read a couple websites and it says that you just have to "guess" it... however, is there a logical way to why you would guess this? Thank you
 
Physics news on Phys.org
The solutions of this EDO are known in terms of Modified Bessel functions or alternately in terms of Parabolic Cylinder functions (in attachment)
 

Attachments

  • EDO 1.JPG
    EDO 1.JPG
    46 KB · Views: 627
For the ODE just use the Frobenius method. Series expansion.
 
Okay i understand, thank you very much
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 16 ·
Replies
16
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 4 ·
Replies
4
Views
3K