Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Inverser Fourier Transform

  1. Jun 23, 2010 #1
    So its been awhile since I've taken PDE, and forgot alot about fourier transforms. Anyways I'm trying to understand what the inverse of the fourier transform actually represents. I understand perfectly how the infinite sum of periodic functions can be used to create any periodic function when summing in respects to your wave number or frequency k, however I don't understand what the inverse of that transform actually represents. It seems that through the inverse you integrate over x to find a function of frequency. What exactly does this function actually represent? Is it a function that can be represented by a sum of x functions ( this statement doesn't even make sense to me )?

    This question is important to me because in my studies of quantum scattering ( or really just any other scattering problems regarding waves ) we deal with k-space which is the inverse fourier transform and I don't completely understand it because of my lack of comprehension of the inverse fourier.

    Thanks you all for the replies
  2. jcsd
  3. Jun 28, 2010 #2


    User Avatar
    Science Advisor
    Gold Member

    The inverse transform of the spectrum is the original function or sequence. In signal processing, the IFT gives the time-domain waveform from the spectrum.

    k-space is also called reciprocal space, and it is the space of the forward (not inverse) transform. Given a crystal lattice in physical space, the lattice in reciprocal space governs scattering, etc. The wavenumber k is a spatial frequency and has units of (1/length). Thus a function (1, 2 or 3-D) in k-space is the spatial spectrum of a physical function (also 1, 2 or 3-D) in real space.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Similar Threads for Inverser Fourier Transform Date
Inverse Fourier Transform May 16, 2012
Inverse Fourier Transform Nov 21, 2011
Stuck on inverse fourier transform pair Jul 17, 2011
Inverse Fourier Transform Aug 2, 2007
Inverse Fourier Transform of Bessel Functions Jan 5, 2006