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In physics, the AdS/CFT correspondence (anti de Sitter/conformal field theory correspondence), sometimes called the Maldacena duality, is the conjectured equivalence between a string theory and gravity defined on one space, and a quantum field theory without gravity defined on the conformal boundary of this space, whose dimension is lower by one or more. The name suggests that the first space is the product of anti de Sitter space (AdS) with some closed manifold like sphere, orbifold, or noncommutative space, and that the quantum field theory is a conformal field theory (CFT).[1]

http://en.wikipedia.org/wiki/AdS/CFT_correspondence

              Synopsis: Gravity Finds a New Partner APS

Gravity dual of the Ising model

Alejandra Castro, Matthias R. Gaberdiel, Thomas Hartman, Alexander Maloney, and Roberto Volpato

Phys. Rev. D 85, 024032 (2012)
Published January 19, 2012
The classical description of gravity fails when looking at interactions at small length scales, but developing a quantum theory for gravity has proven to be one of the most fundamental challenges in physics. For such a theory to be realistic, it needs to describe gravity in four dimensions—three spatial dimensions, plus time. But theorists can learn from simpler, three-dimensional (3D) theories. And, some of these 3D theories for gravity (those in a so-called anti-de Sitter space) can be mapped to two-dimensional conformal field theories, which can be solved. These 2D field theories are said to live at the boundary of spacetime described by the 3D theory for gravity.

Now, in a theoretical paper appearing in Physical Review D, Alejandra Castro of McGill University, Canada, and her colleagues argue that one of these dual conformal field theories is the critical Ising model in two dimensions, a well-understood model for describing magnetic phase transitions in a lattice of interacting spins. The gravity theory involved in this duality is strongly coupled, meaning quantum effects are important.



There are many exactly solvable conformal field theories
(CFTs) in two dimensions, some of which describe
important statistical systems. According to the AdS/CFT
correspondence such theories are expected to be dual to
theories of quantum gravity in three dimensions. Given the
simplicity of the boundary theory, these dualities, if fully
understood, would likely shed light on the nature of holography
and the emergence of geometry from quantum
field theory. Potential examples have been studied in the
semiclassical regime (see e.g. [1–3]) but so far there is no
completely satisfactory example of a fully quantum theory
of gravity which is dual to an exactly solvable 2d CFT.
In this paper we will argue that a class of exactly
solvable CFTs are dual to certain theories of quantum
gravity in AdS3. These are strongly coupled gravity theories
where the AdS radius is Planck scale. Nevertheless, the
path integral of quantum gravity can—with certain assumptions—
be computed exactly and agrees with that of
a known minimal model CFT. The simplest example is the
Ising model, which we conjecture to be dual to Einstein
gravity with a particular (Planck scale) value of the cosmological
constant.

http://physics.aps.org/synopsis-for/10.1103/PhysRevD.85.024032


This requires the past and future horizons to be dS/CFT dual (dark energy) at least for the future horizon. Maybe the past horizon is AdS/CFT dual (dark matter).


Tamara Davis Ph.D. Fig 1.1c
Jan 23

From Robber Barons to Rocket Barons

Posted by: JackSarfatti |
Tagged in: Untagged 
Jack,

Sorry for answering your important email so late. the URL on our new work is not yet ready, as it is the paper, the one we presented to the 100YSS Symposium was just a draft. In the meantime, I can give you and your friends the following preliminary info.

We (me, Nembo and our Austrian colleague Ivanhoe) are very glad that you are interested in our new concept for an ultra-high specific impulse ion thruster based on the Indium FEEP (Field Emission Electric Propulsion) technology. As you know, we have  performed a preliminary study that shows the possibility to realize an ion thruster with specific impulses as high as 100,000 s (Ultra-FEEP), thus enabling very challenging interstellar precursor missions, such as the exploration of the Oort Cloud and beyond. Why an ultra-high specific impulse is so important for these deep-space missions? This way we can reduce the propellant mass from tons to kgs, allowing the spacecraft to accelerate to much higher velocities thus greatly reducing the travel  time.

 
This thruster concept shows unique features if compared to the present ion thruster technologies (including VASIMR):

 
Ionisation directly from a liquid metal (Indium); no need of a high-temperature plasma.
 
Ionisation and acceleration taking place in one step with the same electric field.
 
The most efficient way of carrying propellant, namely in solid state as Indium melts at 157°C.
 
Very low thermal losses as the emitter electrode is kept just same degrees above melting point (157°C).
 
No need for extraction and acceleration grids; erosion risk greatly reduced.
 
NBI ion sources for nuclear fusion research are already working at such ultra-high specific impulses; a new powerful ion source named MITICA is being developed for the ITER project, which will use potentials as high as 1 MV to accelerate a Deuterium ion beam of 40A. However, these ion sources are designed for operational times of just minutes, while ion thrusters for interstellar precursor missions must have a lifetime in the order of 10 years! Severe issues of grid heating and erosion actually limit the maximum acceleration voltage of gridded ion thrusters well below 100 kV. Instead, our novel design of a gridless Indium FEEP Thruster can lead to reliable operation at voltages in the order of 1MV and consequently specific impulses up to 100,000 s.

 

We believe that this is a very promising propulsion concept for enabling exciting deep-space missions, thus paving the way to the real interstellar flight. However, we must advice you that we are in a very early stage of development. Here is a very preliminary road map for you:


1)      Experimental demonstration of the Ultra-FEEP design feasibility; depending on funding amount, from 2 (1M$/year) to 5 (300k$/year) years.

 
2)      Realization of an Engineering Model; from 2 (2M$/year) to 6 (500k$/year) years


3)   Qualification of the technology, including verification of the challenging lifetime; from 5 (2M$/year) to 10(1M$/year) years



This means that with enough funding it is possible to qualify this technology in about 10 years. In parallel we hope that a suitable (light and powerful) power source will be available (< 1kg/kW); as you suggested, maybe cold fusion or Pellegrini´s idea.



I hope that you can find this preliminary information interesting, soon we will send you more details.



Godspeed,

Angelo


Mit freundlichen Grüßen/Best regards

 
Angelo

Electric Propulsion Testing Engineer - Plasma Devices

Electron Devices

Thales Deutschland



--- Dom 1/1/12, JACK SARFATTI ha scritto:

Da: JACK SARFATTI
Oggetto: Re: 100year Italian Star Ship Engineering
A


Angelo
I think your actual engineering would be a good project for some aerospace company like Bigelow Aerospace or Virgin Galactica or something new some of my friends may want to set up. Post the best URL of your work in return email for them to look at. Clearly something of value will come out of what you are doing since you are already past Phase 1 and you are using battle-tested mainstream conventional physics.

Check out Brian Josephson's website on the Italian cold fusion project. He is following it closely. Perhaps that could be your source?

Also check out Gerry Pelligrino's claim of violation of Maxwell's thermodynamic relations in magnetostriction - a possible power source. I do not understand either of the two above claims as I do not understand Woodward's and I am not here and now endorsing any of the three - just suggesting others take a look.


On Jan 1, 2012, at 2:00 PM, Angelo wrote:

Jack,

you are by far too good with us! Troppo buono! We are just two modest italian engineers with a common dream, being able to contribute to the Odissea Interstellare! Our idea of ultra-efficient impulse propulsion can be very good for precursor missions up to 10000 AU, provided that we find a very light power source in the order of MegaWatts!

Best,
Angelo

--- Dom 1/1/12, JACK SARFATTI <sarfatti@pacbell.net> ha scritto:

Da: JACK SARFATTI <sarfatti@pacbell.net>
Oggetto: Re: 100 year Star Ship
A: "Angelo"

Data: Domenica 1 gennaio 2012, 20:24

Hi Angelo
Your work is very good as well as elegant bella figura in the best Italian tradition of Da Vinci.  And if I see an opportunity I will recommend it - most definitely. Your presentation was the best in the actual engineering papers on impulse propulsion at the 100 year Starship Meeting in my opinion. :-)

On Jan 1, 2012, at 2:48 AM, Angelo wrote:

Dear Jack,
 
good to know that there are people ready to invest so much money on exotic propulsion! However, if they want to invest it only when they are sure that an exotic concept works, how can we find the money to demonstrate that it is working without a doubt?
 
By the way, we, Nembo and I, are currently processing the patent on our "slower than light" Ultra-High Specific Impulse FEEP Propulsion! We hope that in 2012 we can find a good guy ready to invest some k€ or k$ on it!
 
It would be also very interesting to set up an experiment to test your idea for a low power warp drive! Is someone already trying to do it?
 
I wish you all the best for 2012! Buon Anno Nuovo!!
 
Angelo & Famiglia
 

Jan 22
click here
Jan 22

Alice through the wormhole 1-21-12

Posted by: JackSarfatti |
Tagged in: Untagged 
http://physics.stackexchange.com/questions/19754/how-long-would-it-take-to-travel-through-a-wormhole
Jan 22

Does gravity glue the electron together?

Posted by: JackSarfatti |
Tagged in: Untagged 
http://physics.stackexchange.com/questions/19515/could-gravity-hold-electron-charge-together
Jan 22

free floating time like geodesics

Posted by: JackSarfatti |
Tagged in: Untagged 
http://physics.stackexchange.com/questions/19758/freefall-in-out-of-an-enclosed-environment
Jan 22

A physics lecture of mine from 1996

Posted by: JackSarfatti |
Tagged in: Untagged 
Just rediscovered

http://www.tu-harburg.de/rzt/rzt/it/sofie/Science.pdf

Jan 18

Zielinski's opinion 1-17-12

Posted by: JackSarfatti |
Tagged in: Untagged 
On Jan 17, 2012, at 10:58 PM, Paul Zielinski wrote:

If this is correct in all details, it's a solid piece of work, and should be published in AJP or Foundations of Physics or
some such journal.

It is very difficult to get a convincing answer to these kinds of questions. No one goes into the required detail.

What you are saying here does make sense to me.


On 1/17/2012 10:35 PM, JACK SARFATTI wrote:
OK here is the answer in standard math notation.

Note the physical speed of light actually measured in the accelerating LNIF is not the same as the formal coordinate speed of light. The physical speed of light is invariant only for those restricted physically relevant general coordinate transformations in which Ray Chiao's gravimagnetic 3-vector potential stays zero before and after the frame transformation. When the gravimagnetic potential is not zero there are generally two distinct physical speeds of light. Also, time contraction opposite to time dilation may be possible - but I am not sure of that. There is also, it seems, the possibility of slowing the physical speed of light to zero and also getting an imaginary speed of light - again I am not sure of that as yet. Since E = Mc^2 that might mean a gravimagnetic shift to negative energy density with application to warp drive. However, this is also very speculative at this point.

Jan 18

Gravimagnetic shift in vacuum speed of light

Posted by: JackSarfatti |
Tagged in: Untagged 
OK here is the answer in standard math notation.

Note the physical speed of light actually measured in the accelerating LNIF is not the same as the formal coordinate speed of light. The physical speed of light is invariant only for those restricted physically relevant general coordinate transformations in which Ray Chiao's gravimagnetic 3-vector potential stays zero before and after the frame transformation. When the gravimagnetic potential is not zero there are generally two distinct physical speeds of light. Also, time contraction opposite to time dilation may be possible - but I am not sure of that. There is also, it seems, the possibility of slowing the physical speed of light to zero and also getting an imaginary speed of light - again I am not sure of that as yet.

See pdf posted today in Library Resources for the equations.
Jan 17
[1 + c(LIF)^-1(g0i/g00)(dx^i/dt) + c(LIF)^-2gij(dx^i/dt)(dx^j/dt)]^-1/2ds(invariant) = c(LIF)dT(LNIF)

GAMMA(LNIF)ds(LNIF) = GAMMA(LNIF')ds(LNIF')

f(LNIF')GAMMA(LNIF) = f(LNIF)GAMMA(LNIF')

f(LNIF')/f(LNIF) = GAMMA(LNIF')/GAMMA(LNIF)

also

f(LNIF')/f(LIF) = GAMMA(LNIF')

because GAMMA(LIF) = 1

note all of these frames are LOCALLY COINCIDENT  

also under certain conditions the LIF can be approximately equivalent to a static LNIF far away from the source.

GAMMA = [1 + c(LIF)^-1(g0i/g00)(dx^i/dt) + c(LIF)^-2gij(dx^i/dt)(dx^j/dt)]^-1/2

= [1 + c(LIF)^-1A.v/g00 + c(LIF)^-2gij(dx^i/dt)(dx^j/dt)]^-1/2