1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Brane universes

  1. Jun 19, 2003 #1
    I have readed a bit about them in an interview to Lisa Randall.

    I have an idea of what they are. But don´t know the detaills of how it is working. That is, they implment the idea of supernumerary dimensios because only gravity can leave the brane (a d-brane if i am not wrong) while the other interactions are fixed to kee in the brane.

    But i would like to know it in more detaill. I didn´t find a good exposition (in fact no exposition) avaiable in line. So in if somene (Jeff?) knows it i would acknowledege a lot if he could give here an explanation. Or at least point a good review.


    P.S. AS you can see althought my prefered theory is LQG i keep open minded to advances in alternative aproximation to QG, as string theory
  2. jcsd
  3. Jun 22, 2003 #2
    I don't know very much about the subject, but seems that there are two approaches to solve the problem of gravitation
    In one model our universe is a D-brane, and particles with spin -1 are open strings with its ends glued to the D-brane. The graviton,has spin-2, is a close string and is not glued to the D-brane, and somehow can travel to other dimensions, this is why gravitation is so feeble
    The other model, the Randall-Sundrum model consist in that our universe is 3-dimensional brane that is parallel to another 3-dimensional brane. This two branes are inside a 5-dimensional spacetime (the bulk). Gravity resides in the other brane, so it has a weak effect in our brane
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook