Fourier transform of function of a complex variable

In summary, the conversation discusses applying the Fourier transform to an analytic function of one complex variable. The speaker mentions starting by writing the function as u + iv, where u and v satisfy the Cauchy-Riemann equations. They also mention taking the Fourier transform of u and v in the usual way for a function of two variables, but note that the Cauchy-Riemann equations set one of the variables to be imaginary. The speaker concludes that the Fourier transform of the full analytic function is possible only if it is zero.
  • #1
thoughtgaze
74
0
Can anyone point me to some material on applying the Fourier transform to the case of an analytic function of one complex variable?

I've tried to generalize it myself, but I want to see if I'm overlooking some important things. I've started by writing the analytic function with

u + iv where u and v satisfy the cauchy riemann equations. I'm tempted to start by saying that to take the Fourier transform of u + iv, simply take the Fourier transform of u and v in the usual way for a function of two variables.

Usually you would have something like u(x,y) → μ(k1, k2) and similarly for v(x,y) → γ(k1, k2)

However, applying the cauchy riemann equations necessarily sets k2 = i k1
and
which implies that the Fourier transform of the full analytic function is simply
μ(k1, k2) =μ(k1)δ(k2 - ik1) = iγ(k1, k2) = iγ(k1)δ(k2 - ik1)

(the δ(k2 - ik1) is just the dirac delta function, which I'm hoping is okay to use even with a complex argument.)

u + iv = ∫dk[2μ(k)]eik(x +iy) = ∫dkdx'dy'2e-i(k(x' - x +i(y'-y))) u(x,y)

μ(k) = ∫dxdy e-ik(x +iy) u(x,y)
 
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  • #2
Update: I am getting that a Fourier transform is possible for the real part and imaginary part of an analytic function iff it is zero.
 

Related to Fourier transform of function of a complex variable

What is the Fourier transform of a function of a complex variable?

The Fourier transform of a function of a complex variable is a mathematical operation that decomposes the function into its constituent frequencies. It is similar to the Fourier transform of a real-valued function, but it takes into account the complex nature of the independent variable.

How is the Fourier transform of a function of a complex variable defined?

The Fourier transform of a function of a complex variable is defined as the integral over the complex plane of the function multiplied by a complex exponential. It is typically denoted by the symbol F{f(z)}.

What is the significance of the Fourier transform of a function of a complex variable?

The Fourier transform of a function of a complex variable is used in many areas of mathematics and physics, such as signal processing, quantum mechanics, and differential equations. It allows us to analyze the frequency components of a complex function, which can provide valuable insights into its behavior.

How is the Fourier transform of a function of a complex variable calculated?

The Fourier transform of a function of a complex variable can be calculated using various methods, such as direct integration, contour integration, and numerical algorithms. The choice of method depends on the specific function and its properties.

How does the Fourier transform of a function of a complex variable differ from the Fourier transform of a real-valued function?

The main difference between the two is that the Fourier transform of a function of a complex variable takes into account the complex nature of the independent variable. This means that the resulting transform will also be a complex-valued function, whereas the Fourier transform of a real-valued function will be a purely real function.

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