Know a simple, linear, complex, eigenvalue BVP?

In summary, the conversation discusses the search for a 1D, linear, complex, 2nd order, eigenvalue BVP that admits analytic solutions. The square well is suggested as a possible problem, but it is ultimately determined that the problem may always reduce to solving a pair of eigenvalue problems for real functions. The speaker clarifies that they are looking for a problem with eigenvalues/vectors that have both real and complex parts, and they are open to a theoretical, rather than real-world, example.
  • #1
member 428835
Hi PF!

I'm trying to find a 1D, linear, complex, 2nd order, eigenvalue BVP: know any that admit analytic solutions? Can't think of any off the top of my head.

Thanks!
 
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  • #3
I take you to mean the function is complex valued over the real line, so it could be written ##f=g(x)+ih(x)##. If the differential equation is linear, then wouldn't the problem always reduce to the solving a pair of eigenvalue problems for real functions, ##g(x)## and ##h(x)##?

Edit: I also meant to ask if you are looking for a real-world example.
 
  • #4
jedishrfu said:
Would the square well be such a problem?
Is this complex? Everything I've checked (here and here) appears to be real.

Haborix said:
I take you to mean the function is complex valued over the real line, so it could be written ##f=g(x)+ih(x)##.
Sorry, perhaps I did not specify: I mean't so that the eigenvalues/vectors have a real and complex part. Perhaps something like ##x''+ix'+x=0##, but I'm at a loss.

Haborix said:
Edit: I also meant to ask if you are looking for a real-world example.
Does not need to be a real-world example. I am looking for a good toy problem to work with.
 

1. What is a simple, linear, complex, eigenvalue BVP?

A simple, linear, complex, eigenvalue BVP (boundary value problem) is a type of mathematical problem that involves finding the values of a function at multiple points, subject to certain boundary conditions. The function is typically a linear combination of simpler functions, and the problem involves finding the eigenvalues (or characteristic values) that satisfy the given conditions.

2. What is the difference between a simple and a complex eigenvalue BVP?

In a simple eigenvalue BVP, the eigenvalues are distinct and the corresponding eigenvectors are linearly independent. In a complex eigenvalue BVP, the eigenvalues may be repeated or complex, and the corresponding eigenvectors may not be linearly independent. This can make the problem more challenging to solve.

3. How is a linear eigenvalue BVP different from a nonlinear one?

In a linear eigenvalue BVP, the function and its derivatives appear in a linear form. This means that the coefficients of the function and its derivatives are constant. In a nonlinear eigenvalue BVP, the function and its derivatives appear in a nonlinear form, meaning the coefficients may vary with the function itself.

4. What is the importance of eigenvalue BVPs in science?

Eigenvalue BVPs are used in many scientific fields, including physics, engineering, and mathematics. They are particularly useful in studying systems that exhibit oscillatory behavior, such as vibrating structures or quantum mechanical systems. They also have applications in solving differential equations and analyzing the stability of systems.

5. How are eigenvalue BVPs solved?

There are several methods for solving eigenvalue BVPs, including analytical methods such as separation of variables and numerical methods such as finite difference or finite element methods. The specific method used depends on the complexity of the problem and the desired level of accuracy. In some cases, the eigenvalues and eigenvectors can also be approximated using computer algorithms.

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