Question

Can anyone explain me about D-Branes??

Answer 1

y not

Answer 2

Then,explain pannunga!

Answer 3

I am hoping to get to attempt to answer this soon (though my knowledge is limited in this aspect), but I am a bit busy at the moment, and my computer has been crashing a lot recently

Answer 4

Waiting for your answer bro! =)

Answer 5

I was hoping to be able to explain some of the aspects of this, and have been reading around in order to do so. But reading up on the subject, I realise that I don't understand it myself, so I dont think I can be of much help, but I will try.

In string theory, there is a postulated number of extra dimensions through which one dimensional stings can vibrate through, with each mode of vibration corresponding to the properties of specific particles. It was discovered that one could extend the dimensionality of strings by an extra dimension (within the extra dimensions), resulting in a vibrating "membrane" or a brane, where these brains can vibrate through the bulk extra-dimensions (So called M-Theory). The term p-brane was introduced where the p denoted a number corresponding to the number of extra dimensions that the brane existed within.

Two types of strings can exist in this formulation, an open string, and a closed string, where the open string can be thought of as a short length of shoe lace, and a closed string like a shoe lace that has been tied into a loop. It was found that open strings had to be confined to p-branes such that their ends were anchored to a d-brane (this is just a p-brane in which exists certain mathematical boundary conditions). This means that they will always be confined to specific membranes. On the other hand closed strings were free to wander from one membrane to another, as they have no ends to anchor to d-branes.

The upshot of this is that open strings correspond to all force particles of the standard model (that is Electromagnetism, strong and weak nuclear forces), and hence all the associated particles and forces are confined to teh same brane and explains why their forces are so strong in comparison to gravity. Gravity on the other hand is a closed string (that is the graviton is a closed string), and can wander through the bulk (i.e. wander between neighbouring branes, effectively leaking of the brane we exist upon) which is why it is much weaker in comparison to the other three forces. This may even explain dark matter, in that gravitons from other branes may leak onto ours, resulting apparently invisible mass that does not interact by the other three forces (which recall cannot leak from other branes onto ours).

So as I understand it, a d-brane is just a specific type of brane in extended string theory, that possesses certain mathematical and physical properties that explain the observed strengths of the four forces.

Answer 6

Thanx bro! =)

Answer 7

You are welcome. I hope it helped, and hasnt caused more confusion. I may be wrong in my understanding of it (and hope some one can correct me if I am) as this is on the limits of my knowledge

Answer 8

Well i will finish reading that book and tell you the corrections if it is there! =)

Answer 9

Happy days. I look forward to it. What book is it that you are reading?

Answer 10

The Little book of string theory and the book you suggested..in search of schrodinger's cat!

Answer 11

I havent read that one. I must add it to my wish list, as it looks interesting.

Answer 12

ok, pannuran