Questions tagged [ads-cft]

AdS/CFT is a special case of the holographic principle. It states that a quantum gravitating theory in Anti-de-Sitter (AdS) space is exactly equivalent to the gauge theory/Conformal Field Theory (CFT) on its boundary.

Filter by
Sorted by
Tagged with
-1
votes
1answer
110 views

CFT dual to rotating black hole

It is known that the dual CFT to Schwarzschild black hole (BH) in AdS is at finite temperature and the temperature is same as the Hawking temperature of the BH. For Reissner-Nordstrom BH in AdS the ...
2
votes
0answers
75 views

Question about general direction of development of application of Tensor Networks to AdS/CFT

I am quite interested in the area of application of Tensor Networks(TNs) to AdS/CFT correspondence. I would like to clarify certain points in order to get better general picture. What is the main ...
4
votes
0answers
120 views

Global $SU(N)$ on the gravity side in AdS/CFT

For AdS/CFT to make sense, symmetries must match between the AdS side and the CFT side. Gauge symmetries are redundancies, not symmetries, therefore the CFT can have a (large) gauge symmetry, say $SU(...
1
vote
1answer
121 views

Definitive form of M/String theory and AdS/CFT role

What is the principal/more actual strategy in order to find the definitive form of M/String theory? I mean, you have a (for example) $10^{500}$ string theory possibilities landscape (given by the ...
8
votes
0answers
185 views

$\mathrm{AdS_3}$ bulk with BTZ black holes and particles in AdS/CFT

Consider three-dimensional anti-de Sitter space $\mathrm{AdS_3}$ treated as the $SL(2,\mathbb{R})$ group manifold, thus parametrised by elements $g \in SL(2,\mathbb{R})$. This space has as isometry ...
2
votes
1answer
225 views

Is metric a classical or a quantum field in General Relativity?

I am currently reading the article of A Castro about $AdS_3/CFT_2$. I have a confusion in reconciling several definitions. It appears that I've understood them imprecisely or may be wrong. These ...
2
votes
1answer
173 views

CFT with noncompact target space => no well-defined vacuum state?

In Maldacena & Nunez's paper, on page 6, when they discuss the compactification of Type-IIB on $\textbf{R}^6 \times K3$ (with D3 branes wrapped on $\textbf{R}^{1,1} \times \Sigma$ where $\Sigma$ ...
4
votes
1answer
267 views

Why don't we consider the representation theory of isometry groups of space-times in curved QFT?

In relativistic quantum field theory, physical quantities such as tensor and spinor can be considered as representations of the Poincaré group $\mathrm{ISO}(d,1)$, the isometry group of the given $(d+...
0
votes
1answer
162 views

holography dual in flat spacetime

In AdS/CFT the bulk geometry is AdS spacetime, the flat limit of AdS is taking to the radius of AdS to infinity. By taking this limit can one get the holography dual in flat spacetime from AdS/CFT, or ...
2
votes
0answers
254 views

$\mathrm{AdS}_3$ Bulk-to-bulk propagator in global coordinates

What is the expression of Bulk-to-bulk propagator in global coordinates? I mean, I know that there is the standard expression in terms of hypergemotric funciton depending on the invariant chordal ...
1
vote
0answers
132 views

Central Charge of large $N$ Gauge theory in 't Hooft limit

It is well known that large N gauge theory in t'Hooft limit has central charge ~ $N^2$ I want to convince myself in this by considering simple example of: 1 flavor(meaning that we have only one ...
33
votes
3answers
8k views

Why is Sachdev-Ye-Kitaev (SYK) Model model important?

In the past one or two years, there are a lot of papers about the Sachdev-Ye-Kitaev Model (SYK) model, which I think is an example of $\mathrm{AdS}_2/\mathrm{CFT}_1$ correspondence. Why is this model ...
2
votes
1answer
129 views

Differences and relations between CFTs defined on the complex plane and CFTs defined on the torus?

What are the differences and relations between CFTs defined on the complex plane and CFTs defined on the torus? Are they supposed to be the same CFTs? I think they should have the same spectra of ...
3
votes
1answer
157 views

Distinction between holographic entanglement entropy and thermal entropy

Given a system $A$ and its complement $\bar{A}$, we know that the entanglement entropy is given by $$ S_A = - \text{Tr} ( \rho_A \log \rho_A ), $$ where $\rho_A$ is the reduced density matrix ...
3
votes
2answers
829 views

Why is there a Cardy formula in 2D CFT?

In 2d CFTs, we have the Cardy formula which tells us the number of states, which can be derived from the partition function by using modular invariance. What special property of 2D CFTs make it ...
8
votes
2answers
371 views

Relation between CS/WZW and AdS/CFT

One precise example of realization of the holographic principle is the CS/WZW correspondence, which relates 3d Chern-Simons theory with the 2d Wess-Zumino-Witten model. As explained for example in ...
3
votes
1answer
371 views

Applicability of Ryu-Takayanagi formula for boundary regions which do not belong to constant time slice

While reading article "Entanglement Entropy of Extremal BTZ" I saw a phrase: In the more general case where the entangling interval does not lie in a single time slice of the boundary, the Ryu–...
3
votes
0answers
97 views

Matrix Model in AdS/CFT & exact results

Matrix models appeared in the context of AdS/CFT while trying to calculate the Circular Wilson Loop. It was first noted by Erickson, Semenoff & Zarembo [hep-th/0003055] that the 2-loop ...
2
votes
0answers
48 views

Shooting Method for coefficient matching in holography

Usually when one is attempting to solve the equations of motion of a bulk field in the AdS/CFT framework the main goal is to understand if a corresponding boundary operator aqcuires a VEV (commonly ...
9
votes
1answer
222 views

AdS/CFT, QCD & String Phenomenology

The AdS/CFT correspondence in its prototypical case states that $\mathcal{N}=4$ Super Yang-Mills is dual to string theory in an $AdS_5 \times S^5$ background. Since this duality is of the type strong/...
1
vote
1answer
217 views

Continuous spectrum implies divergent partition function

I have encountered a statement which I don't understand: When the energy spectrum is continuous above a certain minimum energy, the partition function $Z$ diverges for all $Re(\beta)>0$, where $Z=...
4
votes
0answers
123 views

Subtleties in AdS$_2$/CFT$_1$

I was looking at few papers on AdS$_2$/CFT$_1$. It seems to me that this is not as well studied as the higher dimensional dualities (e.g, AdS$_3$/CFT$_2$ or AdS$_5$/CFT$_4$). Can someone summarize ...
2
votes
1answer
192 views

D3-brane in AdS/CFT correspondance

I was reading a paper by Veronika Hubeny The AdS/CFT correspondence 1. Maldacena chose a D3-brane system to derive his conjecture. So I was wondering, why "D3-brane"? In other words, I need to know ...
1
vote
1answer
142 views

Importance of AdS boundary

I was reading a chapter about Anti-de Sitter space-time, it was mentioned that it has a boundary and this boundary is its most striking feature. Note that they weren't taking about the AdS/CFT ...
5
votes
1answer
199 views

Is $\mathcal{N} = 4$ SYM a “toy model”?

The second sentence of the Wikipedia article on $\mathcal{N} = 4$ supersymmetric Yang-Mills theory describes it as "a simplified toy theory." But the AdS/CFT correspondence conjectures that it is ...
3
votes
1answer
277 views

Large $N$ expansion vs AdS/CFT

I'm beginning to learn AdS/CFT and I have an elementary question. It is said that since it is very hard to calculate 4 point and above correlators in a strongly coupled CFT, we can use instead the ...
1
vote
0answers
127 views

How is the two-point function of an operator dual to a scalar ADS field obtained in ADS/CFT?

The two point function of an operator dual to a scalar field in ADS/CFT can obtained directly from computation of the on-shell action in momentum space and then taking it back to position space. The ...
5
votes
1answer
251 views

AdS Black holes

How is the mass of the black hole defined in a asymptotcally AdS solution of the black hole? How can I find it? Beacause in asymptotcally flat solution I can read it from the $g_{tt}$ component of the ...
4
votes
1answer
401 views

Correlator of energy-momentum tensor and OPE

In http://arxiv.org/abs/hep-th/9108028 Equation (2.22), the correlation function of then energy-momentum tensor with some primary fields is We can view this as sum over the OPE of the energy-...
3
votes
1answer
140 views

Implication of non-positive tripartite information

Hayden et al 2011 showed that tripartite information is non-positive given Ryu-Takanayagi formula. (For definition of tripartite information, see for instance section 4.4 of this paper) Is there ...
3
votes
1answer
309 views

Circular Wilson Loop in AdS/CFT

I'm trying to get the AdS solution to the circular wilson loop. The standard AdS metric is: $ds^2 = \frac{L^2}{z^2}(\eta_{\mu \nu} dx^{\mu} dx^{\nu} + dz^2)$ If I take the circle of radius R at ...
2
votes
1answer
65 views

Are the quasinormal modes scalar quantities?

I am studying the so-called quasinormal modes (QNMs) in the context of the AdS/CFT correspondence and I got stuck. For instance, if I choose a weird patch of coordinates for the, say, AdS5-...
2
votes
0answers
73 views

What is the origin of the five-form field in bubbling Ads geometries?

I have been reading the paper: Bubbling Ads space and the 1/2 BPS geometries[hep-th/0409174]. In the paper they look at 1/2 BPS states in the field theory which are dual to D3 branes IIB supegravity. ...
7
votes
0answers
79 views

Collapse of two large black holes in AdS

In $4d$ flat space, two black holes of mass $M$ can collapse to form another one of (roughly) mass $2M$. This process is spontaneous, as reflected by the fact that the black hole entropy $S=M^2$ ...
1
vote
0answers
44 views

Norm definition for arbitrary spin fields in AdS

In AdS/CFT one usually hears of normalizable and non-normalizable modes regarding the independent solutions for the different fields. I've found that the "natural" definition of the norm in the case ...
4
votes
2answers
733 views

Bulk-to-Boundary propagator

How can I show that the bulk-to-boundary propagator $$ K(z,x;x')~=~\frac{z^{\Delta}}{[z^2+(x-x')^2]^{\Delta}} \tag{1} $$ goes as a delta function near the boundary $$ K(z,x;x')~\sim ~z^{d-\Delta}\...
1
vote
0answers
104 views

Applying AdS-CFT to traversable wormholes? [closed]

ER=EPR recently brought up the connection between non-traversable wormholes and entanglements. What about traversable wormholes? Can we apply AdS/CFT to traversable wormholes?
1
vote
0answers
186 views

Density of states from the Retarded Green's function for a rotating black hole

I have been studying the scattering of a scalar field around a rotating black hole in the near-horizon extremal limit. The radial solution provides the retarded Green's function, just by taking the ...
2
votes
0answers
58 views

Ads/CFT coordinates

I have an AdS space written in Poincare' coordinates and in global coordinates. The transformation that brings one set in the other is a conformal transformation?
2
votes
0answers
256 views

Scalar Field in Global AdS

I have to solve the Klein Gordon equation for a scalar field, in global $AdS_3$ (covering space, with non periodic $\tau$) written as $$ ds^2=\frac{R^2}{\cos^2\rho}(-d\tau^2+d\rho^2+\sin^2\rho d\theta^...
0
votes
0answers
54 views

What is a zero temperature horizon?

While reading the paper "Disorder horizons: Holography of randomly disordered fixed points" by Hartnoll and Santos, I came across this: We are interested in solutions with a zero temperature ...
0
votes
1answer
193 views

Scalar fields in AdS$_3$

I'm looking at lecture notes on AdS/CFT by Jared Kaplan, and in section 4.2 he claims that the action for a free scalar field in AdS$_3$ is $$S=\int dt d\rho d\theta \dfrac{\sin\rho}{\cos\rho}\dfrac{1}...
4
votes
1answer
297 views

Wilson Loop in AdS/CFT

In AdS/CFT correspondence one can compare results in $\mathcal{N}=4$ SYM with string theory type IIB in $AdS_5 \times S^5$. One of the observables that it's possible to get non-perturbative results is ...
0
votes
1answer
104 views

The energy of dual boundary field in AdS/CFT

In AdS/CFT, when the spacetime is a planar AdS black hole with dimension ($d+1$), the corresponding energy of boundary field theory is proportional to the black hole mass parameter. For example when $...
5
votes
0answers
182 views

Reference request: QFT and AdS/CFT for information theorists

There is a lot of buzz recently about connections between quantum information theory and quantum field theory/string theory. I would like to understand in particular how quantum information methods ...
2
votes
0answers
101 views

$\mathcal{N}=4$ SYM on a rotating three-sphere

In the following paper: http://arxiv.org/abs/hep-th/9911124, the authors claim that the dual field theory to the five dimensional Kerr-AdS black hole is a $\mathcal{N}=4$ SYM on a rotating three-...
3
votes
0answers
66 views

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 ...
3
votes
1answer
340 views

Sub-Ads scale resolution of pluperfect tensor network

I am currently reading article "Bidirectional holographic codes and sub-AdS locality". [I] This article presents tensor networks which are built from so called pluperfect tensors. Authors claim that ...
1
vote
0answers
103 views

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. ...
3
votes
1answer
971 views

What is a Witten diagram?

Recently I heard the terminology of Witten diagram. Studying QFT, I frequently see Feynman diagrams and use them to compute scattering amplitudes, one-loop corrections and so on. In string theory ...