Can Green Functions Help Solve Differential Equations?

  • Thread starter eljose
  • Start date
  • Tags
    Inverse
In summary, the conversation discusses the construction and use of Green functions in solving differential equations. The main topic is the relationship between the Green function LG(x,s) and the linear differential operator L, with a focus on using Fourier and Laplace transforms. The speakers share their knowledge and experiences with Green functions and suggest looking into using Laplace transforms for solving Cauchy problems in linear ODEs.
  • #1
eljose
492
0
we all know that given a differential equation Ly=a0(x)y+a1(x)Dy+a2(x)D^2y=0 with Dy=dy/dx we can construct a Green function so LG(x,s)=d(x-s) being d the delta function.

My question is this given the G(x,s) could we construct the L so LG(x,s)=d(x-s) could someone provide an example of how to obtain?..thanks.
 
Physics news on Phys.org
  • #2
HINT:Fourier transformed of the Green function coincides with the inverse of the Fourier transformed of the LINEAR differential operator...

Daniel.

P.S.Think aboout Poisson's equation for an infinite domain.
 
  • #3
You mean F[G(x,s)]=1/F[L(y)] so then F^-1[1/G(x,s)]=L(y) does the same happen with the Laplace transform?...
 
  • #4
I've never used Green functions and Laplace transforms...I told you what i knew...Maybe someone else could enlighten you more.

What i do know is that Cauchy problems in LINEAR ode's are dealt nicely by Laplace transform...But i don't recall some Green functions having been used...

Daniel.
 

1. What is Green's inverse problem?

Green's inverse problem is a mathematical concept in which the solution to an inverse problem is expressed in terms of the Green's function, which represents the response of a system to a point source. In simpler terms, it is a method for finding the unknown source or cause of a known effect.

2. How is Green's inverse problem used in science?

Green's inverse problem is used in a wide range of scientific fields, including physics, engineering, and geology. It is commonly used to determine the location and magnitude of earthquakes, to study the flow of groundwater, and to analyze the properties of materials.

3. What are the challenges of solving Green's inverse problem?

One of the main challenges of solving Green's inverse problem is dealing with the non-uniqueness of solutions. This means that there can be multiple possible solutions that fit the observed data, making it difficult to determine the exact source or cause. Additionally, the complexity and non-linearity of many systems make it challenging to accurately model and solve the problem.

4. How is Green's inverse problem related to other inverse problems?

Green's inverse problem is a specific type of inverse problem that involves finding the cause or source of a known effect. Other types of inverse problems include parameter estimation, image reconstruction, and optimization problems. Green's inverse problem is often used as a foundation for solving more complex inverse problems.

5. What are some applications of Green's inverse problem?

Green's inverse problem has many applications in various fields. It is commonly used in seismology to locate earthquake sources and determine their magnitude. It is also used in medical imaging to reconstruct images from measurements, and in environmental studies to map the flow of pollutants in groundwater. Additionally, Green's inverse problem is used in materials science to analyze the properties of materials and in geology to study the Earth's subsurface structure.

Similar threads

Replies
6
Views
2K
  • Differential Equations
Replies
1
Views
1K
  • Differential Equations
Replies
1
Views
1K
  • Differential Equations
Replies
1
Views
2K
  • Differential Equations
Replies
3
Views
2K
  • Differential Equations
Replies
2
Views
975
  • Differential Equations
Replies
1
Views
742
  • Differential Equations
Replies
20
Views
2K
  • Differential Equations
2
Replies
52
Views
776
  • Differential Equations
Replies
4
Views
2K
Back
Top