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

What are B mode and E mode signals?

  1. Feb 9, 2007 #1
    I've read an article in nature and found technical words "B mode signal" and "E mode signal". I don't understand what they are. In a website, they say it's like the electromagnetic field line but I'm still not clear.

    I also don't understand what k means in " the linear greyscale shows the E-mode lensing convergence field k(Kappa)". I think it's also the technial word.

    The article is about the dark matter maps.
  2. jcsd
  3. Feb 10, 2007 #2


    User Avatar
    Science Advisor

    I do not know the details but this is known as E-B mode decomposition. Basically the E-mode is a measure of the stretching (shear) of the light source that is weak lensed. This mode is curl free and is generated by gravitational effects. As far as I know the other mode maps, the B-mode maps, are the noise components that cannot be identified with the gravitational physics of the lens.

    You may want to read this article about gravitational lensing basics:

    And this one about E-B mode decomposition (end of the page):
    http://www.lsst.org/Science/Cosmic_Shear.shtml [Broken]
    Last edited by a moderator: May 2, 2017
  4. Feb 11, 2007 #3
    Thank you very much, Mr Hellfire.

    I'll try to search again from those links.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook