How Can I Transform My O.D.E. into Sturm-Liouville Form?

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Discussion Overview

The discussion revolves around transforming a given ordinary differential equation (O.D.E) into Sturm-Liouville form. Participants explore methods for finding a function f(x) that can be normalized, while addressing the challenges of solving the equation and considering alternative expressions.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant presents an O.D.E in a near Sturm-Liouville form and seeks input on finding a suitable function f(x) for normalization.
  • Another participant suggests investigating modified Bessel functions or the Parametric Bessel equation as potential related forms.
  • A different participant points out that the equation is inhomogeneous and relates it to the quantum harmonic oscillator, mentioning that solutions involve Hermite functions.
  • One participant provides a general solution to the O.D.E using Whittaker functions, indicating the presence of arbitrary constants in the solution.

Areas of Agreement / Disagreement

Participants express differing views on the nature of the equation and potential methods for solving it, indicating that multiple competing approaches and interpretations remain in the discussion.

Contextual Notes

Some assumptions about the constants and the specific form of the O.D.E are not fully detailed, and the implications of the inhomogeneous nature of the equation are not resolved.

Who May Find This Useful

Readers interested in differential equations, particularly those studying Sturm-Liouville theory, quantum mechanics, or mathematical methods in physics may find this discussion relevant.

kalphakomega
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Close to Sturm-Liouville form...

I got an O.D.E down to the form

fll(x) + ([tex]\lambda[/tex] - 16x2)f(x) = 0

I omitted some constants to make it look simple. What I'm trying to do is find a function f(x) to normalize. Solving by using roots ended up giving me an exponential function I am unable to solve. However I think if I could convert the above to proper Sturm-Liouville form I might find an alternative expression for y(x) so that I could normalize its square. Any thoughts? I'm not completely competent in the aspects D.E as of yet so I may have missed a simpler route. Input is greatly appreciated.
 
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You look into modified Bessel, Parametric Bessel equation? I don't have the answer, just look very similar to one of those.
 
I don't know what you mean by using roots, but your equation is inhomogeneous. This is actually a rescaled version of the quantum harmonic oscillator, the solutions of which are given in terms of Hermite functions. Look here for a concise reference:
http://www.fisica.net/quantica/quantum_harmonic_oscillator_lecture.pdf
 


The general solution to your ODE is as follows

[tex]f(x) = \frac{1}{\sqrt{x}}[C_1 WhittakerM(\frac{\lambda}{16},\frac{1}{4},4x^2)+C_2 WhittakerW(\frac{\lambda}{16},\frac{1}{4},4x^2)][/tex]

where C1 and C2 are arbitrary constants.
 

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