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
25
votes
0answers
341 views

Quantum statistics of branes

Quantum statistics of particles (bosons, fermions, anyons) arises due to the possible topologies of curves in $D$-dimensional spacetime winding around each other What happens if we replace particles ...
19
votes
2answers
2k views

Why one-dimensional strings, but not higher-dimensional shells/membranes?

One way that I've seen to sort-of motivate string theory is to 'generalize' the relativistic point particle action, resulting in the Nambu-Goto action. However, once you see how to make this '...
13
votes
2answers
626 views

Why should the modes of the linearized metric perturbation be “wavefunctions” of gravitons (in the Randall-Sundrum model)?

In "An Alternative to Compactification" by Randall and Sundrum, they discuss the localization of "graviton modes" around the Planck brane in the Randall-Sundrum model where we have ...
12
votes
1answer
561 views

What, exactly, is a “delta function p-form” as used in the theory of branes?

In string theory, when dealing with branes, the following happens: We rewrite a worldvolume action $S = \int_{\Sigma_{p+1}} \omega^{(p+1)}$ of a $D_p$-brane as an integral over the whole $\mathbb{R}^{...
11
votes
2answers
343 views

Is it possible to bound a single D0-brane to a D4-brane?

I'm studying the Jafferis solution for twisted $N=4$ Yang-Mills theory in four dimensions from the paper Crystals and intersecting branes. Consider the problem of computing the charges of the allowed ...
10
votes
2answers
181 views

Is there a description of D-branes from the worldsheet CFT perspective?

D-branes are best known as hypersurfaces in spacetime on which open strings with Dirichlet boundary conditions can end. Furthermore, they have several geometric properties associated with them, such ...
10
votes
1answer
3k views

Electric charge in string theory

The mass of an elementary particle in string theory is related with the way the string vibrates. The more frantically a string vibrates the more energy it posses and hence the more massive it is. My ...
10
votes
1answer
145 views

Matrix geometry for F-strings

A stack of N D-branes has the strange property that the traverse D-brane coordinates are matrix-valued. When the matrices commute, they can be interpreted as ordinary coordinates for N ...
10
votes
1answer
760 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 ...
10
votes
1answer
327 views

What happens when two D-branes annihilate?

What happens when two D-branes annihilate? Do we get a radiation of strings?
9
votes
1answer
967 views

M(atrix) theory and things other than D0-branes? And is it non-peturbative M-theory or non-peturbative Type IIA theory?

When I first read the BFSS Paper on M(atrix)-theory, I was under the impression that it was a non-peturbative formulation of M-theory. But recently, upon reading this paper of Nathan Seiberg's, I ...
9
votes
1answer
932 views

What does it mean to “wrap” a D-brane around some manifold?

I am getting quite confused with this terminology when I read the papers. Like while constructing the near horizon $AdS_3$ in the $D1-D5$ system one considers $IIB$ on $R^{1,4}\times M^4 \times S^1$ ...
9
votes
1answer
183 views

The action of the Kaluza–Klein reduction (Chapter 4 of “D-branes (Clifford Johnson)”)

In the first part of Section 4, the author gives \begin{equation} S = \frac1{16\pi G^N_{(5)}}\int(-G_{(5)})^{1/2}R^{(5)}d^5x = \frac1{16\pi G^N_{(4)}}\int(-G_{(4)})^{1/2}\Big(R^{(4)} - \frac32\...
9
votes
1answer
224 views

Black p-branes vs. fundamental branes

After the duality revolution, we learned about the important role of both, black p-branes and p-branes. However, sometimes their fundamental definition is confused in the literature. I mean the ...
8
votes
1answer
527 views

The stability of D-Brane

In "String Theory and M-Theory: a modern introduction" by K.Becker, M. Becker and J.H.Schwarz, they say that BPS D-brane is stable as it preserves half of the Supersymmetry. I really want to ...
8
votes
1answer
255 views

Counting D0-D4 Bound States

I have a slightly technical combinatorics question. Consider the degeneracy $D_n$ of bound states of $n$ D0 branes and one D4 brane. This is given in Polchinski by (13.6.24), \begin{align} \sum_{n=0}...
8
votes
1answer
843 views

What is the difference between D branes, M branes, and NS branes?

I know that D$p$ branes are branes with $p$ spatial dimension with satisfying Dirichlet boundary condition. I want to confirm the following things. First, I heard the D-branes are massive, and these ...
8
votes
1answer
428 views

Is it possible to derive the brane action in pure supergravity?

The branes that source the RR fields of supergravity are described by the DBI action plus a CS term. I know this only from superstring considerations. Is there a way to find this result without ...
8
votes
1answer
333 views

Critical dimension in quantization of p-branes

So I have what might be a fairly basic question, but my understanding that in the quantization of the the string, or the 1-brane, there are conditions on the number of spacetime dimensions to ensure ...
8
votes
2answers
272 views

5-branes in Topological String Theory (TST)

It is known that the topological A-model allows the existence of $\frac{1}{2} \left[ D + \mathrm{rank} \left( B \right) \right]$-dimensional branes, where $D$ is a dimensionality of spacetime, and $B$ ...
8
votes
1answer
1k views

String frame and Einstein frame for a Dp-brane

The low energy effective action for $N$ D$p$-branes in the string frame is $$ S_\text{eff} = \frac{1}{16\pi G_{10}}\int d^{10}x \sqrt{-g}\ e^{-2\phi}(R+ 4(\partial\phi)^2+\cdots) $$ where $R$ is the ...
7
votes
3answers
540 views

How to find the rank of the matrix $\frac{\partial ^2\mathcal{L}}{\partial \dot{X^\mu} \partial \dot{X^\nu} }$ for the Nambu-Goto string Lagrangian?

In this case $$\mathcal{L}~=~-T\sqrt{-\dot{X^2}X'^2+(\dot{X}\cdot X')^2}.$$ I was reading some books and papers about the constraints in the Nambu-Goto action, and all of them say something like the ...
7
votes
1answer
345 views

Type II Superstring and Open String

I would like to trow away some confusion I'm accumulating. Usually when superstrings are introducted (see for example Wikipedia) one says: Type I is a theory of open and closed strings, while Type II ...
7
votes
2answers
1k views

Why M-theory has only M2 and M5 branes?

Why M-theory has only M2 and M5 branes? In string theory, depending on the type one considers, you get all kind of D-branes. What is so special in M-theory that only allows 2 and 5 branes?
7
votes
1answer
414 views

D-branes in type II string theory

D-branes, as I currently understand them, are submanifolds of spacetime on which open strings can end with Dirichlet boundary conditions. On the other hand, type II string theory is a theory of ...
7
votes
1answer
1k views

What exactly is a fundamental string as opposed to a D-string?

What exactly is a "fundamental string" in string theory? For bosonic string theory we have the bosonic string inside a 26-dimensional target space. Introducing supersymmetry, we have the ...
7
votes
1answer
334 views

Questions on D branes and their role in the AdS/CFT correspondence

I'm a beginner in learning the AdS/CFT correspondence, and I come across two problems that I hope an answer will be given here. D branes in string theory are usually introduced through the T-duality ...
7
votes
4answers
136 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 ...
7
votes
1answer
261 views

Mass of a superstring between two branes?

A open bosonic string between two parallel branes seems to obey formulae such as $M^2 = \big((n + {\theta_i - \theta_j \over 2 \pi}) {R' \over \alpha'}\big)^2 + {N-1 \over \alpha'} $ So that the ...
7
votes
1answer
366 views

Does Type IIB string theory feature D(-1) and D9 branes?

I'm slightly confused as to how one deduces the D-brane content of a string theory by studying the p-form fields in the effective field theory. In type IIB supergravity one has: The Kalb-Ramond 2-...
7
votes
1answer
192 views

Disappearance of moduli for condensate of open strings

Consider a Dp-brane. Compactify $d$ spatial dimensions over a torus $T^d$. Suppose $d\geqslant p$, and that the Dp-brane is completely wrapped around the compactified dimensions. Look at the open ...
7
votes
0answers
351 views

Open conjectures on the Fukaya category

This is ported from mathoverflow question https://mathoverflow.net/q/263693/. Can somebody give examples to open conjectures on the behavior of the $Fuk(M,ω)$ (that's the "mathematical A-model ...
6
votes
1answer
176 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 ...
6
votes
2answers
351 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 ...
6
votes
1answer
778 views

Why are there no branes in heterotic string theory?

Why does the heterotic string (or heterotic supergravity) have no brane solutions? According to David Tong's notes: the heterotic string doesn’t have (finite energy) D-branes. This is due to an ...
6
votes
1answer
198 views

A question about the coupling between string and gauge field $A_{\mu}$

I have a question about deriving the coupling term of string and the gauge field on brane. According to David Tong's lecture note p184/(191 in acrobat), the coupling is given by $$ S_{\mathrm{end-...
6
votes
0answers
137 views

Why does a string connected between a D0-brane and an anti-D0-brane turn into a tachyon upon their annihilation?

Consider a string stretched between a D0-brane and an anti-D0-brane. In this case as the stretching energy is greater than the quantum zero point energy the string will have a positive mass. But, as ...
5
votes
1answer
681 views

The theory of strings stretching between intersecting D-branes

I am trying to understand various aspects of intersecting D-branes in terms of the gauge theories on the worldvolume of the D-branes. One thing I'd like to understand is the worldvolume action for ...
5
votes
1answer
322 views

Why does unbroken supersymmetry imply the absence of tachyons?

Just a quick question, same as in the title. I'm trying to understand stable D-branes.
5
votes
1answer
944 views

D branes Ns brane and p-branes

It is now a common knowledge that "D-p branes are equivalent to p-branes" due to Polchinski's work. Note that D-p branes are objects in string theory and p-branes are objects in blackhole theory. So ...
5
votes
1answer
240 views

How can one modify the Nambu-Goto action to include the longitudinal degrees of motion?

The Nambu-Goto action is given by $$ S = -\frac{T_0}{c} \int_{-\infty}^{+\infty} d\tau \int_{0}^{\sigma} d\sigma \sqrt{ \Bigg(\frac{\partial X^\mu}{\partial \tau} \frac{\partial X_\mu}{\partial \...
5
votes
1answer
128 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 ...
5
votes
1answer
112 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 ...
5
votes
1answer
128 views

Higgs mechanism on a brane- application to a 2d superconductor

In usual three-dimensional superconductors the would-be Goldstone mode is eaten up by the electromagnetic gauge field via the standard Higgs mechanism. I am thinking now about a problem of a two-...
5
votes
1answer
137 views

AdS/CFT dual of $N$ D$p$-branes at finite temperature

The gravity dual of $N$ D$p$-branes at zero temperature is $$ ds^2= H^{-1/2}(r)(-dt^2+dx_p^2) + H^{1/2}(r)(dr^2 + r^2d\Omega_{8-p}^2) $$ with $$ H(r) = 1 + \left(\frac{R}{r}\right)^{7-p} $$ what ...
5
votes
0answers
138 views

$T$-duality in effective gauge theories of a $D(p+1)$-brane

I am considering a $D(p+1)$-brane in a space $\mathbb R^{1,p}\times S_R^1$ where $S_R^1$ is the circle of radius $R$. I am assuming low energies $ER\ll1$, so that only the massless spectrum of the ...
5
votes
0answers
124 views

Transformation of the string coefficient under T-duality

I am trying to study an effective string theory valid in the low energy limit $ER<<1$. The effective action corresponds to a $D(p+1)$-brane in $R^{1,p}\times S^1$ and it is given by $$S_{D(p+1)} ...
5
votes
0answers
115 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 ...
5
votes
0answers
143 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 ...
5
votes
0answers
85 views

Finding the Hilbert expansion of a D4 Coulomb branch

I am trying to compute the HS of the following Coulomb branch, but first I am not sure how to proceed in interpreting the diagram and what variables to use. I am trying to use the equation from this ...

1
2 3 4 5 6