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Questions tagged [holographic-principle]

The Holographic principle is a principle of string theories and a supposed property of quantum gravity that states that the information within a region is exactly described by that on its boundary. DO NOT USE THIS TAG for a photographic hologram.

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Holographic dualities and strong subbadditivity of entanglement entropy

Recent analysis of inequalities satisfied by entanglement entropy in AdS bulk duals have led to establishing an equivalence between Strong Subadditivity and the Null Energy Condition (NEC) How hard ...
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How is encoded the information on the surface of the volume' s boundary?

In the context of the holographic principle, who states that the entropy of ordinary mass (not just black holes) is also proportional to surface area and not volume;that volume itself is illusory ...
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Is there an equivalence between Boltzmann entropy and Shannon entropy..?

I have already parse other posts about this subject but none of them seems to answer completely to my interogation [ this interrogation is to put in relation with this question Is there an ...
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Is there an equivalence between information, energy and matter?

Consider the physical world as made of information, with energy and matter as incidentals. This statement must be placed in the context of the holographic principle and the works of Bekenstein ... ...
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Form of Light-Cone in pure $AdS_3$

There is a picture in the article of Harlow which (in particular) represents light cone in $AdS_3$. Note that point X has nonzero radial coordinate. If point X has zero radial coordinate it is quite ...
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In AdS/CFT, are the CFT states defined only on the boundary, or is it only the boundary theory that matters?

To be more specific than the title allows: Gauge/gravity duality says that gauge theories on the boundary of an asymptotically AdS space are dual to gravitational theories in the bulk. I know the ...
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Black holes in AdS/CFT

In Swingle's work Entanglement Renormalization and Holography, he mentioned that a black hole in AdS bulk corresponds to a finite temperature boundary state. With the MERA picture of the entanglement ...
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How can the information encoded in a boundary be changed in holographic principle?

When information is encoded in a lower dimensional boundary of a bulk, following the holographic principle, it would raise a universe in the boundary with physics determined by the information encoded ...
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Holographic principle and spacetime singularities

This is a quite conceptual question, but I found it interesting. The holographic principle states that, roughly, any system containing gravity can be described on a theory on its surface. It applies ...
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Can physics of n dimensions work in n-1 or n+1 dimensions?

Can 3D physics work in 2D? I mean, could 3D laws of physics exist in a 2D space? In Ads/CFT duality, for example, laws of physics in a 3D space (AdS) work in analogy with 2D laws of physics (CFT). ...
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339 views

How does holographic duality work?

In holographic theories about the universe, the one being in the boundary of the space, takes information of the higher dimensional universe, so, two different theories can describe the two universes. ...
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Could an holographic universe consist of 3d embedded in 4d instead of 3d embedded in 2d?

In the holographic model, information about a given dimension can be embedded in a lower dimension, so our 3d universe could be considered as a 2d one. Could it happen the other way? I mean, could the ...
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Variation of scalar field action

I am reading Polchinski's review on AdS/CFT . I have a very simple question, and please help me out. Thanks in advanced. The question is about formula (3.19). The scalar effective bulk action is ...
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Confused by Maldacena video about AdS/CFT

I was watching this https://www.youtube.com/watch?v=Iz2ie3i1Gh0 about Ads/CFT. Very nice video from the master himself. I got confused though about what he calls $N$. Basically he says $N$ is the ...
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Holographic principle where it stops and why

I just read "Black hole wars" by L. Susskind. Essentially he claims that a boundary contains all the information about the volume it encompasses. He proclaims this the holographic principle (HP). My ...
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What is fundamental in the AdS/CFT holographic universe formulation of String theory?

I have a lot of confusion about the AdS/CFT with holography. Does it show that strings and branes are excitations of fields on the conformal boundary of the universe (CFT)? Can someone explain the AdS/...
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Is the Universe created from Vacuum Fluctuations? [closed]

I would be interested to hear what people think about this idea for a paper. It has been speculated that the universe is a zero-energy vacuum fluctuation (E.P.Tryon Nature 1973). I attempt to show ...
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Holography on non-AdS spacetime

I have a question regarding AdS/CFT and what it teaches about our world. AdS/CFT if often treated as our best tool to explore quantum gravity, and people have worked very hard in trying to understand ...
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Is there anything actually inside a black hole, do they actually exist?

When objects fall into a black hole, observers outside the black hole will never see the object cross the event horizon because the object's time slows down and will stop at the event horizon. The ...
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Is Rovelli's argument a compelling argument for baby universes?

A Recent Rovelli's paper argues that black hole states accessible in the interior exceed those that are given by the holographic bound observed externally. It seems that in principle, right before ...
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Issues with de Sitter Space and Conformal Field Theory

As a de Sitter universe is more convenient for cosmology, what are the current issues with a dS/CFT type correspondence? Earlier work by Strominger, seemed promising but I haven't heard of additional ...
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Do Liouville theory have a gravity dual?

Does Liouville theory have a gravity dual? I think the answer is not. But what's wrong with Liouville theory? What features of Liouville theory are universal for other CFTs?
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How is AdS / CFT a “successful realisation” of the holographic principle?

According to the Wikipedia articles of both AdS/CFT correspondence and the Holographic principle state that the former was a 'successful realisation of the latter. Does that mean that the Holographic ...
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Quenched systems - disorder average (SYK model)

In a system with quenched disorder one is usually looking for self-averaging quantities, i.e., quantities such that the average over the couplings produces a ``typical" configuration in the ...
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Wilson loop in AdS/CFT : string interpretation

It is well known that Wilson loop is a quite hard observable to compute. In the case in which the QFT is dual to a gravitation theory in AdS space, we can use holography to compute the Wilson loop, ...
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More (Dense) Information in Bulk than on Surface?

The entropy of a Schwarzschild black hole is proportional to $m^2$ where $m$ is the mass of the black hole. The volume of the black hole would be proportional to $m^3$ and the area would be ...
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463 views

How to show that Chern number gives the amount of edge states?

When talking about topological insulator and talking about bulk-edge correspondence, it seems to be widely accepted conclusion that the band Chern number (winding number) is equal to, when the ...
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Hilbert space structure of quantum mechanics in the context of holography

These is a question about the Hilbert space structure of quantum mechanics in the context of holography. See page 175 of Thomas Hartman's notes on Quantum Gravity and Black Holes. In quantum ...
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Holographic geodesic derivation in AdS3 and BTZ

I am trying to derive equation 2.4 in the article https://arxiv.org/pdf/hep-th/0603001.pdf The AdS3 metric in global coordinates $(t,\rho,\theta)$ is given by \begin{align} ds^2=R^2(-\cosh^2\rho dt^2+...
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When to trust Holography?

AdS/CFT correspondence allows us to compute $n$-point functions of a CFT by means of solving on-shell gravitational action in anti-de Sitter space. If I understand correctly, considering classical ...
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Yang-Mills/topological string theory (M-theory) duality

It is known that there is a duality between Chern-Simons theory on 3-fold $X$ and topological A-model on the cotangent bundle of this manifold, $T^*X$ (see, for example, the original paper by Witten, ...
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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 ...
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Holography and General Relativity

Sometimes, the holographic principle is stated as follows: "Every theory with gravity in D-dimensions (in certain preexistent space-time background) can be described by a (D-1)-field theory WITHOUT ...
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What is the physical analog of the projection in Holographic Universe hypothesis?

I am a layperson and do not have a good understanding of the background elements of this question. Please forgive and correct if I make any untrue statements. I understand that Holographic Principle ...
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Did they find evidence of holographic universe?

In the article they say: Theory claims to offer the first 'evidence' our Universe is a hologram From reading the article I can't really see what the evidence is. Can someone tell me what the ...
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Bekenstein bound and “dimensionality” of information (entropy)

The Bekenstein bound says that the maximum entropy which can be contained in a (spherical) volume of space with a given amount of energy is proportional to the amount of energy multiplied by the "...
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171 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 ...
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Recommended reading about Holographic Principle

Please recommend papers/books/blogs for someone trying to learn about the Holographic Principle, assuming that person has knowledge of the undergraduate mathematics and physics major level.
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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 ...
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Has Verlinde's theory made significant advance recently?

In 2010-2011, Verlinde's theory for explaining gravity as emergent from thermodynamics started to get known in the physics community. It was (and seemingly still is) lacking evidence, and faced ...
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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 ...
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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 ...
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String Theory Vs. Holographic Theory of the Universe. Compatibility [closed]

String Theory claims strings to be one dimensional objects vs. dimensionless point particles of the Standard Model. String Theory also needs 10 or possibly more spatial dimensions to operate in. ...
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How rigorous is the description of the edge of the Kitaev Honeycomb as a CFT?

My understanding of the Kitaev honeycomb model is that high-level abstract properties (anyons and their braid statistics) can be seen to emerge the microscopics of the model (fermions and vortices). ...
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Seeking clarification about a discussion of the Holographic Principle in Sean Carroll's book

I am reading Sean Carroll's pop-science book 'From Eternity to Here' and am having trouble connecting the links in his discussion of the Holographic Principle. At the outset, I would ask that you try ...
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Could gravitational waves have a large entropy in quantum gravity?

The question is broad, and we still don't know what is quantum gravity. But let me be more specific. In the question (on this site, see below) on whether gravitational waves have entropy the answers ...
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Has anyone explored a possible duality between quantum gravity and statistical mechanics?

There is a well known duality between quantum mechanics in D dimensions and classical statistical mechanics in D+1 dimensions. Specifically, the Euclidean version of the path integral in D dimensions ...
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Do December 2015 Fermilab Holometer experiment results suggest space-time not discretely emergent?

I read the December 2015 paper Search for Space-Time Correlations from the Planck Scale with the Fermilab Holometer available here and looked at the various related posts here at PSE. It seems to me ...
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what is the metric of N-sheeted $AdS_3$?

Suppose the AdS$_3$ metric is given by $$ ds^2 =d\rho^2+cosh^2\rho d\psi^2 +sinh^2 \rho d\phi^2 $$ what is the n-sheeted space of it? Can the n-sheeted BTZ be constructed from it by identifications ...
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About the holographic principle

I read at a book this quote "As the degrees of freedom of a particle are the product of all the degrees of freedom of its sub-particles, were a particle to have infinite subdivisions into lower-...