What is the composition of branes and how are they held together?

[Fiziqs]

I'm not sure which forum these questions belong in, so the moderators should feel free to move this thread to wherever they deem appropriate.

I have some questions regarding branes. These questions are based upon a complete lack of understanding about the nature of branes, and as they build upon this fundamental lack of understanding some of them are no doubt completely ridiculous. Please answer any questions you choose, and ignore the others. The first two questions are the most important as the others are simply an extension of my view that D1-branes would have a positive and a negative end.

1. The most basic question I suppose, is what are branes made of, and what force holds them together?
2. Could it be said that a D1-brane has a positive and a negative end?
3. Would a vibration on a D1-brane flow from one end to the other, or would it be a standing wave?
4. Could energy of some sort be said to flow through a D1-brane under the right conditions?
5. If all the matter in our universe were sucked into a black hole, would it form a D0 or a D1 brane?
6. Could a D2-brane have a positive and negative aspect?
7. Rather than interacting at random could branes actually be attracted to each other?
8. Are black holes in some sense a D1-brane extended outward from a D2 or higher brane?
9. If so does a black hole then grow until it makes contact with another brane, at which time it's contents are discharged, in a sense similar to an electrical discharge into the other brane?
10. Could gravity be the attraction between two branes?
11. When two D2-branes interact do they combine to form a larger D2-brane, or would they in a sense become laminated to form a higher dimensional brane?

Sorry for all the stupid questions. But this is the best way that I have found to learn something. Read, ask questions, contemplate, and repeat.

Like I said the first two questions are the most important. I have many more questions, but any information that you can give would be appreciated.

Thanks

 

[haael]

1. The most basic question I suppose, is what are branes made of, and what force holds them together?

There are not made of anything. What is a knot on a rope made from? What is a hole in a cheese made from?

Branes in string theories are basic object in a sense. You could explain everything with them, but they themselves do not have any simpler explanation.

2. Could it be said that a D1-brane has a positive and a negative end?

Yes, there are theories in which branes are oriented.

3. Would a vibration on a D1-brane flow from one end to the other, or would it be a standing wave?

Both situations are possible.

4. Could energy of some sort be said to flow through a D1-brane under the right conditions?

Yes, the vibrations energy.

5. If all the matter in our universe were sucked into a black hole, would it form a D0 or a D1 brane?

Uh, God only knows. Which theory are you referring to?

6. Could a D2-brane have a positive and negative aspect?

Yes, surfaces can also be oriented. But there are surfaces like a Moebius strip that have only one side and they can not be oriented.

7. Rather than interacting at random could branes actually be attracted to each other?

Yes, they could and this is what string theories are about.

8. Are black holes in some sense a D1-brane extended outward from a D2 or higher brane?

Once again: in which theory? But considering how many string theories there are I bet there is one where black holes are described just like that :).

10. Could gravity be the attraction between two branes?

Yes, in a sense that the gravity is a manifestation of some fundamental brane interaction.

11. When two D2-branes interact do they combine to form a larger D2-brane, or would they in a sense become laminated to form a higher dimensional brane?

They form another D2-brane.

 

[Naty1]

1. The most basic question I suppose, is what are branes made of, and what force holds them together?

There are not made of anything. What is a knot on a rope made from? What is a hole in a cheese made from?

I disagree: Branes are multi dimensional strings and hence are composed of energy like strings. Ed Witten found that [M theory includes] such objects with p dimensions, meaning integer values from 0 to 10...and such p=branes are significantly heaver than strings.

In THE ENDLESS UNIVERSE, for example, Neil Turok and Paul Steinhardt describe forever colliding brane [energy] ripples from which collision irregularites in space and time produce the quantum fluctuations associated with 'bangs'...the start of another universe.

"Could a D2-brane have a positive and negative aspect?"
yes, but my understanding is not via 'charge'...rather by the nature of vibrational energy patterns. One end of an open string may 'behave' differently that the other end.

 

[haael]

I disagree: Branes are multi dimensional strings and hence are composed of energy like strings.

What does it mean: "to be composed of energy"? Everything is composed of energy, so this sentence is just a tautology. Moreover, in string theories "energy" is not some basic entity whose properties are known for given. Rather, the branes are basic objects and the "energy" is explained in terms of branes.

Branes in string theories are the conceptually most basic objects, like axioms in mathematics. Their properties can not be described by anything more simple, be it energy.

 

[Naty1]

The OP can decide whether he likes 'nothing' or the energy perspective of Kip Thorne, Leonard Susskind, Paul Steinhardt, Neil Turok, Roger Penrose, Brian Greene...,,,,well you get the idea...

In any case, the 'energy' description is useful because different energy vibrational patterns of strings result in different observational patterns, like mass, charge, spin,etc.