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.

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335 views

What makes the strings (or $p$-branes) that occur in string theory vibrate?

A normal spring (for example in my ballpoint) is made of particles that interact with each other wich makes the string vibrate with a frequency that depends on the material (the particles). Now a ...
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D4 branes ending on NS5 branes (Witten's construction): query about harmonic functions

This query stems from Witten's paper, ''Solutions of Four-Dimensional Field Theories via M Theory'' (hep-th/9703166). Specifically, consider Type IIA string theory, and suppose one has a stack of NS5 ...
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Superstring mass between 2 D-branes

The mass of a superstring between 2 parallel D-branes of dimension $p$ and $q$ is $$m^2=(N−a)+(y/2π)^2$$ But what is the value of the normal ordering constant $a$?
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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-...
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Could a 3+1 space be embedded in a 4+1 space and retain its 3+1 characteristics? [closed]

I'm confused because I can conceptualize this embedding scenario in two seemingly incompatible ways. Which of the following scenarios are possible?: 1) 4+1 space automatically enforces 4 dimensions ...
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153 views

Non-perturbative Brane effects

In Johnson's Book about D-branes he gets the Tension of a D brane: $$\tau_p = \frac{\sqrt{\pi}}{16 \kappa_0 g_s}(4\pi^2\alpha')^{(11-p)/2}$$ By performing a string amplitude calculation and ...
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Rotating Branes and AdS/CFT

Do we have an extension of the AdS/CFT correspondence for rotating branes? Are the rotating branes, the supergravity analog of the Kerr Black Holes in General Relativity? What are the most ...
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What is known about the physics of Planckbrane (another brane) in Randall–Sundrum model?

Randall–Sundrum model imagines that our universe is a five-dimensional anti-de Sitter space and the elementary particles except for the graviton are localized on a (3 + 1)-dimensional brane or branes. ...
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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-...
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What are the difference between a black holes and a black branes? [closed]

I want to know the fundamental difference between a black hole and a black brane? What is the planar limit?
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Brane interactions?

In particle physics, in QFT's, interactions come from the interaction piece in the Lagrangian (action). In string theory, waiting for a complete formulation of SFT, we have to add "by hand" ...
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What is the relationship between a brane, a manifold, and a space?

I've read many ways to define manifold; one way is to define it as a type of mathematical space (a type of topological space to be exact). All of the definitions that I've seen for brane, on the ...
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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 ...
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What's between the branes?

So I'm doing my best to explain M Theory to some friends... Mind you, I'm no expert... When we finally got past the obstacle of more than three dimensions... which can be difficult for folks who aren'...
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Is M-Theory and 11D Supergravity the same thing?

Is M-Theory and 11D Supergravity the same thing? Reading Hawking, he uses 11D Supergravity and M-Theory interchangeably. http://www.hawking.org.uk/quantum-cosmology-m-theory-and-the-anthropic-...
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What would happen if two branes collided and stuck together?

There is a theory that the universe began when two "branes" bumped each other, creating the energy that sparked the beginning of our universe. What if instead of separating, they actually stuck, ...
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DBI action with Weyl Invariance

The DBI action, given by $$S_{Dp}=-T_p\int d^{p+1}\xi e^{-\phi(\xi)}\sqrt{-\textrm{det}\left(G_{ab}(\xi)+B_{ab}(\xi)+2\pi{\alpha}'F_{ab}(\xi)\right)}$$ is diff and Poincaré invariant. I want to ...
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In M theory, what size are the branes/D branes?

In string theory strings are around Planck length, but how big are the D branes in M theory? Can we see them with the LHC?
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Bulk action - Can a brane velocity be defined?

a) If a brane action in a bulk is defined, in that case, that a brane is modelwise moving through a bulk, how is this ratio defined? Is this a regular "velocity" in that meaning, that space is being ...
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In M theory, can a fundamental open string attach to a M5 brane?

I only saw a couple of pages online that showed this so i guess I'll ask on here, can fundamental open 1 string end on an M5 brane?
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1answer
485 views

In M Theory, what does the M5 brane look like?

In M theory, the fundamental 1 strings are made out of the compactification of an M2 brane. In String Theory: Volume 2, Superstring Theory and Beyond By Joseph Polchinski Pg. 204 He states that ...
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1answer
134 views

In M-theory, are strings created by membranes?

In M-theory there are 2- and 5-branes, but where are the one-dimensional strings which are responsible for all the particles? Can 5-branes turn into 1-dimensional strings due to compactification?
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Sources that explain strings between two branes, where one brane ends on the other

I can't seem to find a source that explains what happens when there are strings between one brane and another brane, where one brane ends on the other brane. For example, consider a D3-brane ending on ...
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M-theory and Mathematics [closed]

If the framework of M-theory is the right path for a unification of gravity with quantum mechanics, is it obligatory to believe that, at a certain level, reality is not just easily describable by ...
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Concerning topology of BPS states of the M5-brane

My question is about the M5-brane in M-theory. I would like to know whether the BPS states of the M5-brane worldvolume theory (especially the 1/2 BPS and 1/4 BPS ones) are independent of the topology ...
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Fayet-Iliopolous Parameters from Separation of NS5-branes in $(x_{7}, x_{8}, x_{9})$: An ambiguity as to which gauge group the FI parameter belongs

hep-th/9611230v3, page 12 explains how, for a configuration of D3s along $(x_{1}, x_{2}, x_{6})$, and NS5's along $(x_{1}, x_{2}, x_{3}, x_{4}, x_{5})$, the Fayet-Iliopolous D-term coefficient $\zeta$ ...
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Connection between the M5 brane and (2, 0) superconformal field theory

I have read that the worldvolume theory of the M5 brane is a $(2, 0)$ superconformal field theory (SCFT). But I have also learnt from talks that the $(2, 0)$ theory lacks a Lagrangian description. ...
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Type I string theory on $K3 \times \mathbb T^2/\mathbb Z_2$ and the K3 orbifold limit

Consider Type IIB string theory with 4 O7-planes and 32 D7-branes on $K3 \times \mathbb T^2/\mathbb Z_2$. The K3 induces D3-charge on their world-volumes which can be cancelled by the introduction of ...
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D-brane tension of type I D9-branes after T-duality

Type I contains branes with a brane tension which is $\frac{1}{\sqrt 2}$ times that of type II branes. The reason is that, e.g., in the computation of the D9-D9 amplitude the open string is unoriented....
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Creation of a miniature universe?

I am not referring to the experiment being conducted at Lancaster University involving liquid helium and a magnetic field to build a marble sized representation of the early cosmos. My question is: ...
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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 ...
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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 ...
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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 ...
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When can a $k$-cycle wrap around a manifold?

According to the paper ``Heterotic and Type I String Dynamics from Eleven Dimensions'' (page 7): Even when the topology is wrong -- for instance on $\mathbb{R}^{11}$ where there is no two-cycle for ...
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Projector and delta function on a cycle $\Sigma$ of a manifold $\mathcal{M}_6$

In the paper ``Hierarchies from Fluxes in String Compactifications'' by Giddings, Kachru and Polchinski, the following example is considered for a localized source that may have negative tension (my ...
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Branes at the conifold

Consider $N$ $D3$-branes at the singularity of the conifold. This particular example can be viewed as a $AdS_{5} \times T^{1,1}$ in the near horizon limit, where the Einstein manifold has isometry $SU(...
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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 ...
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Branes wrapping curves in M-theory. What does it mean?

What does it mean that a M5-branes wraps a holomorphic curve in M-theory? In specific a lot of Vafa's paper involve various branes (not only M5) wrapping some cycles. What does this really mean ...
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Supersymmetries of the type IIB D3-brane action

The following query is based on a reading of section 2.2 of a paper by Graña and Polchinski. The idea is to begin with the D3 brane action of the form $$ ds^2 = Z^{-1/2}\eta_{\mu\nu}dx^\mu dx^\nu + Z^...
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How to design an experiment to see if we are living in a brane or not?

Theories in string theory and cosmology lead to an idea that our universe is a single "membrane" (or brane, as it is commonly called) suspended within a higher dimensional "bulk". See Wikipedia. Is ...
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Can a brane have infinite volume?

I'm asking this within the framework of brane theory. My intuition is that branes are objects with finite volume, but then how can they accomodate an Universe that is infinite in extent?
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From String Frame to Einstein Frame for 10D supergravity

This question is related to but not answered in the post String frame and Einstein frame for a Dp-brane, so it should be treated as a separate question. Beginning with the gravity action $$S = \frac{...
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1answer
640 views

Curvature of Weyl-rescaled metric from curvature of original metric

I'm trying to go from the low-energy effective action in the string-frame to the corresponding action in the Einstein frame. The action in the string frame has the form $$S = \frac{1}{(2\pi)^7 l_s^8}\...
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The low dimensional end of the brane scan

Common wisdom says that only the top dimensional part of the brane scan of Green-Schwarz super p-brane sigma models is quantum consistent (the critical strings and the M-branes). But by the results in ...
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Higher dimension world possibility [duplicate]

Could it be possible that all of the unexplained phenomena (like uncertainty) in our 4D world might be originated from a higher dimension universe? If so, then of course we'll never observe the ...
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1answer
948 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 ...
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1answer
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How can extra (non-curled up) dimensions be hidden from us?

Wikipedia says: If extra dimensions exist, they must be hidden from us by some physical mechanism. One well-studied possibility is that the extra dimensions may be "curled up" at such tiny ...
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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?
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369 views

What does it mean the term “probe brane”?

What does it exactly mean the term "probe brane"? People say for example: We put a stack of N branes at some point and then a probe brane ..." How do they appear in AdS/CFT? Can you give me an ...
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Quivers Representations in SUSY gauge theories

I would like to hear some reasons and ideas on how quivers are useful in SUSY gauge theories. There is a nice answer about the case of D-branes here but it is not clear on their appearance in gauge ...