About the complex error function

In summary, the conversation discusses the complex error function w(z), also known as the Faddeyeva function, and a related identity on page 297 of Abramowitz. The identity involves the integral of e^{-t^2} over a certain range, and it is stated that this is equal to e^{-z^2} times the complementary error function. The speaker is seeking a proof for this identity and provides a helpful resource for further information.
  • #1
luisgml_2000
49
0
Hello!

I'm studying on my own the complex error function [tex]w(z)[/tex], also known as Faddeyeva function. On page 297 from Abramowitz it is stated that
$$
\frac{i}{\pi} \int_0^{\infty} \frac{e^{-t^2}}{z-t}\, dt=e^{-z^2}\operatorname{erfc}(-iz)
$$
where

[tex]
\operatorname{erfc}(z)=\frac{2}{\sqrt{\pi}}\int_z^\infty e^{-t^2} \, dt
[/tex]

The former identity is puzzling me and therefore I can't come up with a proof for it. Welcome any suggestions!

Thanks in advance for your attention.
 
Last edited by a moderator:
Physics news on Phys.org

1. What is the complex error function?

The complex error function, also known as the Faddeeva function, is a mathematical function that is used to calculate the error function for complex valued arguments. It is defined as the integral of the Gaussian function from 0 to x, and is denoted by w(z).

2. How is the complex error function related to the error function?

The complex error function is an extension of the error function, which is defined for real arguments. It can be expressed in terms of the error function as w(z) = e^(-z^2) * (1 - erf(-iz)).

3. What are the applications of the complex error function?

The complex error function has various applications in mathematics, physics, and engineering. It is commonly used in probability theory, statistics, and signal processing to calculate the probability of a normally distributed random variable. It is also used in the study of electromagnetic fields and the analysis of heat transfer in engineering problems.

4. What are some properties of the complex error function?

The complex error function has several important properties, including being an entire function (meaning it is analytic everywhere in the complex plane), having a branch cut along the negative real axis, and satisfying the functional equation w(z) = e^(-z^2) * (1 - w(-z)). It also has a Taylor series expansion and can be approximated using various numerical methods.

5. Are there any special values of the complex error function?

Yes, there are several special values of the complex error function that are commonly used in calculations. These include w(0) = 0, w(i∞) = 1, w(-i∞) = -1, w(∞) = 0.5 + i0, and w(-∞) = -0.5 + i0. These values can be derived from the definition of the complex error function and its relationship to the error function.

Similar threads

Replies
5
Views
1K
Replies
4
Views
744
Replies
3
Views
696
Replies
4
Views
1K
Replies
3
Views
1K
Replies
21
Views
816
Replies
1
Views
932
Replies
1
Views
1K
Replies
3
Views
1K
Back
Top