Questions tagged [branes]

A (p-)brane is a dynamically evolving physical object that generalizes the notion of a point particle to (p) higher dimensions. A point particle can be viewed as a brane of dimension zero, a string as a brane of dimension one, and a membrane (sheet) as a brane of dimension two. Do not use for particles or strings, however, unless in comparative juxtapositions.

Filter by
Sorted by
Tagged with
1
vote
0answers
27 views

How does gravity leak to other dimensions, if extra dimensions existed?

There was research article that showed the gravitational waves and electromagnetic waves propagated through the universe the same way, loosing energy by the inverse square law. The researchers ...
2
votes
0answers
27 views

Chemical potentials for $D$-brane bound states

This question is about a mathematical subtlety arising in the computation of the partition function of a supersymmetric ensemble of some lower dimensional $D$-branes attached to a stack of higher ...
1
vote
0answers
48 views

Show that a system of intersecting $D4$-$D6$ branes is supersymmetric

The paper "Supersymmetric Gauge Theories, Intersecting Branes and Free Fermions" asserts (first paragraph, page 12,section 2.4) that a system of $N$ $D4$-branes intersecting with $k$ $D6$ ...
0
votes
2answers
80 views

What is brane inflation, and can it be eternal?

What is Brane Inflation and how does it describe inflation process? Can it be eternal?
2
votes
0answers
27 views

Born-Infeld term for $D$-brane low energy effective action

I am trying to reproduce the Born-Infeld term for the $D$-brane action as explained in Szabo's BUSSTEP Lectures and must admit I am utterly confused by some of the steps. This is a long and technical ...
2
votes
0answers
61 views

$(p,q)$-5 webs from $M$-Theory

The authors of the paper "Webs of (p,q) 5-branes, Five Dimensional Field Theories and Grid Diagrams" consider type $IIB$ superstring theory compactified on a circle $S^{1}$ and claim (in ...
3
votes
0answers
41 views

D-brane, and SUSY charges

The following results summarize the relation between orientifold and D-brane, and SUSY charge $$ \begin{array}{l||c|c|c|c|c|c}\text{orientifold} &\text{O4} & \text{O3} & \text{O2} &\...
0
votes
0answers
19 views

How can a membrane be a solution of 11D supergravity?

What does it mean that an M2 brane is a solution of 11D supergravity? Does this mean that there is some sort of black hole whose singularity is stretched out into a sheet like a membrane? So that the ...
0
votes
1answer
88 views

Why aren't black holes the same as M2 branes?

If there was an M2-brane with the topology of a sphere. Then I can't see why there are not the same thing? They both have the same topology if we consider the black hole event horizon. Both seem to ...
8
votes
4answers
126 views

The nature of the space in which we exist

I'm looking for pointers to give me a better understanding as to what 'space' is. I do not mean the descriptions of what's in 'space' i.e. not interested in descriptions of outer space filled with ...
1
vote
0answers
37 views

Tension and horizon radius of brane (String theory and M-theory by Katrin Becker)

In exercise 12.1 tells the relation between $N_2$, the number of M2-brane, and $r_2$, the horizon radius. The following relation is derived $$-g_{00} = -1 + \frac{16\pi G_{11}N_2T_\text{M2}}{9\...
5
votes
0answers
68 views

D-branes as the atoms of Calabi-Yau crystals

I'm studying the Nishinaka-Yoshida crystal models that encode the generating function of $D4$-$D2$-$D0$ BPS bound states on a Calabi-Yau divisor. The case of conifold at its singular point is ...
3
votes
1answer
75 views

Seeking intuitive explanations regarding $A_{n-1}$ singularities

I am studying Ben Craps' lecture notes Big Bang Models In String Theory for my undergraduate thesis. I am not well versed in topology, and would like intuitive explanations for certain ideas regarding ...
0
votes
1answer
65 views

Can branes in string theory be described by different systems of mathematics or logic?

Mathematically, in string theory, branes can be described using the notion of a category and the mathematical category theory says that logic can change from one category to another. We can build ...
4
votes
1answer
117 views

D8 branes in M-theory

The following table gives us the correspondence between objects in Type IIA Superstring theory and M-theory: The D6 brane is magnetically dual to the D (10-6-4) = D0 brane and so magnetically couples ...
3
votes
2answers
94 views

Does an infinitely large thin plate produce a uniform $g$-field near its surface according to GR?

I had an argument with contributor @safesphere regarding this problem. He insists that an infinitely large plate with a finite surface density of $\sigma$ would eventually collapse into a black hole ...
2
votes
1answer
102 views

Why is the Polyakov action special for $p\!=\!1$ branes?

Reading this article I ran into a doubt. It derives the Polyakov action for a general $p$-brane $$S(X,g)=-\frac{T}{2}\int\text{d}^{p+1}\xi\,\sqrt{-g}\left(g^{ab}h_{ab}-(p-1)\right)\tag{7}$$ by ...
3
votes
2answers
128 views

2 coinciding D-branes leads to a $U(2)$ gauge theory

I'm having trouble understanding how two D-branes leads to a $U(2)$ gauge theory from David Tong's notes, chapter 7, pages 191-192. I am learning group theory and I understand that a 'charge' is a ...
1
vote
1answer
112 views

Scattering amplitude of open + closed strings and D-Branes

When calculating the scattering amplitude of $n$ open string tachyons and $m$ closed string tachyons on the disk, I'd like to understand why choosing the open string tachyons to be attached to $D_{25}$...
2
votes
1answer
76 views

Does different “side” of D-branes matter?

The picture of wiki showed some strings attached on D-branes. However, consider those D2 branes in 3 dimensional world. Then D2 branes had two "sides". Case 1. Let a string started at one of ...
3
votes
0answers
107 views

What is an NS-2 brane?

This question is about topological string theory and it was also posted in MathOverflow. The existence of a new brane called "an NS-2 brane" is predicted in (the second paragraph in the page ...
5
votes
1answer
109 views

D-brane analogue in ordinary QFT

I am reading David Tong's lectures on string theory and on the page 180 in chapter 7 of his lecture notes http://www.damtp.cam.ac.uk/user/tong/string.html : he claims that D-branes are something in ...
1
vote
1answer
71 views

How do branes come into existence according to string theory? [closed]

How do branes come into existence according to string theory? Also what are branes made out of?
0
votes
0answers
44 views

Why is the worldvolume theory a $U(1)$ gauge theory?

So in string theory a Dp-brane can be described by a $(p+1)$ dimensional QFT living in its worldvolume. For a string, this is similar to the description of the string as a twodimensional QFT living ...
1
vote
0answers
78 views

What is NS5 brane?

NS5 brane can be considered as 1/2 BPS solution in supergravity (with other solutions to compare): This branes of Type IIA/B supergravity are expected to extend to solutions of the full Type IIA/B ...
2
votes
0answers
42 views

‘t Hooft loops, yang mills, and “free energy”

When reading through the N=4 SYM s-duality literature, one will encounter some interesting properties i.e. twists (on boundary conditions), non-trivial electric and magnetic fluxes, the so called “...
6
votes
2answers
292 views

Path integral for fermion on circle

I am trying to understand talk by Edward Witten Nonsupersymmetric D-Branes and the Kitaev Fermion Chain. More concretely, I wanna to understand this slide: If I try to calculate such path integral I ...
1
vote
0answers
32 views

Conformal symmetry extension for super p-branes?

Conformal symmetry plays a vital role in string and superstring theories. Why can not we generalize conformal symmetry to objects of greater dimensions as branes? Where are we with this puzzle in 2020?...
3
votes
1answer
88 views

How does the $D$-brane geometry influence the gauge symmetries?

I am trying to understand why the $D$-brane structure of a string theory matters for string phenomenology. From what I understood from Wikipedia, the $D$-brane structure determines the gauge ...
0
votes
0answers
60 views

Why is de Sitter spacetime a better model of our universe than brane world models?

Why is it assumed that we live in a de Sitter space-time? Besides the de Sitter Lambda Cold Dark Matter model, there are Anti de Sitter brane world models, which also generates Friedmann equations ...
1
vote
0answers
31 views

Branes ending on branes

From Polchinski book, I know that a one-dimensional brane can end on a higher dimensional brane. However, I was wondering if an even more generic picture could be developed, where a $(p+1)$-...
1
vote
0answers
69 views

D7-brane in Type IIB and axio-dilaton

In the context of Type IIB string theory with one D7-brane we have the following situation. The axio-dilaton complex scalar is defined by $\tau:= C_0+i e^{-\phi}$ where $C_0$ is the axion and $\phi$ ...
1
vote
0answers
94 views

Could dark matter actually be matter which resides in a different spatial dimension? [closed]

I have at best a rudimentary understanding of the math in this side of physics, so bear with me. I am also aware of this question, but it was asked and answered 4 years ago and I don't want to ...
3
votes
0answers
92 views

Why D-brane can be attached to NS5 branes?

Is it possible (in analogy with D-brane) understand appearance of NS5 brane in perturbative string spectrum? Why D-brane can be attached to NS5 branes? I know that this can be described using notion ...
3
votes
1answer
66 views

How I can get the numerical factor in the relation between string coupling and YM coupling?

I'm trying to understand some references about Wilson loops being used to test AdS/CFT. Some of them are Nadav Drukker, David J. Gross: An Exact Prediction of N=4 SUSYM Theory for String Theory ...
4
votes
1answer
108 views

How does a Lagrangian with delta potential transform to a Hamiltonian?

Suppose the Lagrangian was given as: $$L = \frac{1}{2}\int_{-\infty}^{\infty} \underbrace{\left(\dot{A(}z)^2-A(z)^2\right)+\left(\dot{Q(}z)^2\delta(z)-Q(z)^2\delta(z)\right)+2\dot{Q(}z)\cdot A(z) \...
2
votes
0answers
92 views

Is Randall-Sundrum model background independent?

Randall-Sundrum model (https://en.wikipedia.org/wiki/Randall%E2%80%93Sundrum_model) is related on string theory. String theory can be background independent (https://en.wikipedia.org/wiki/...
1
vote
0answers
38 views

Tachyon mode in Brane-Antibrane system (Type II)

Lets First start with coincident $D3$ brane- $D3$ Brane system. Superstring stretch between these two contain a Tachyon mode But GSO projection removes this. For open string, $D$ branes serve just as ...
1
vote
0answers
49 views

Why are Goldstone bosons associated to translation symmetry breaking corresponding to the coordinates transverse to the D-brane?

In some lecture notes, in the presence of a Dp-brane, translational symmetry is broken in the direction transverse to the brane. However, they identify the coordinates, $$\Phi^a,\quad a=p+1,\cdots,D-1$...
0
votes
1answer
50 views

In M-Theory are membranes excited states of a field? [duplicate]

Are M2 and M5 membranes in M-Theory excited states of some underlying field, or are they fundamental? In what sense are membranes solitonic? In the reference question, someone made a comment that had ...
1
vote
0answers
59 views

What is the relation between a $D_2$-brane and an $M2$-brane?

I am only familiar with the concept of a $D_2$-brane from a first course in String theory. I would like to learn, at least on a conceptual level, what an $M2$-brane is and what is its relation to the $...
1
vote
0answers
46 views

Differentiating D3 brane worldvolume theories with NS5 brane and NS5 antibrane boundary conditions

In 'Supersymmetric Boundary Conditions in N=4 Super Yang-Mills Theory', Gaiotto and Witten derive boundary conditions for the worldvolume theory of the D3 brane. In particular the boundary conditions (...
0
votes
1answer
157 views

What does a closed 3-brane look like?

A closed 2-brane looks like a donut, or in scientific terms, a torus. This is a three-dimensional object. I came across this diagram in a book, "The Little Book of String Theory". A torus is a three-...
10
votes
1answer
729 views

Why does only gravity leak into extra non-compact dimensions?

This article K. Pardo, et. al., Limits on the number of spacetime dimensions from GW170817, Journal of Cosmology and Astroparticle Physics, Vol. 2018, 2018. which was published recently in JCAP ...
5
votes
0answers
132 views

World-volume (higher) gauge theory on D-branes

It is well known that if one constructs ordinary WZW type sigma model for string action, it is possible whenever they find a cocycle in appropriate Chevalley-Eilenberg algebra. If I understand it ...
0
votes
0answers
52 views

What are the known ways to model baryons in string theory?

As I understand, string theory models baryons by including a so called "baryon vertex". Is this right? It seems that baryon vertex's are usually D/M branes. Is that always the case?
3
votes
1answer
111 views

Wrapped M2 brane gauge field coupling?

An M2 brane is coupled to the C3 field of SUGRA. And as you all know, a wrapped M2 brane gives us the fundamental string. My question is, does the wrapped M2 brane (fundamental string) still couple ...
2
votes
1answer
137 views

How does magnetic charge in string theory arise?

In string theory, all of the standard model charges (electric, color, and weak hypercharge) arise from Kaluza Klein theory and through the interactions between strings and branes. But little is said ...
1
vote
1answer
105 views

Have string theory and brane cosmology the same landscape?

Has any of these hypothetical theories a "higher" number of possible universes or has string theory landscape the same type of possible universes than brane cosmology?
1
vote
0answers
138 views

Derivation of Born-Infeld (BI) for D-brane

I am trying to reproduce derivation of the Born-Infeld (BI) action for D-branes as it is presented in R.J. Szabo, BUSSTEPP Lectures on String Theory, arXiv:hep-th/0207142. In particular, I don't ...

1
2 3 4 5