Does de Sitter General Relativity Offer a New Approach to Quantum Gravity?

[Uncle Al]

http://arxiv.org/abs/0711.2274

The cosmological constant is claimed to be tamed and computable.
Curious...

"The Poincare' group generalizes the Galilei group for high-velocity
kinematics. The de Sitter group is here assumed to go one step
further, generalizing Poincare' as the group governing high-energy
kinematics. Algebraically, this is done by supplementing spacetime
translations with proper conformal transformations. This change in
special relativity implies concomitant changes in general relativity
-- yielding a de Sitter general relativity. The source current turns
out to include now, in addition to energy-momentum, the proper
conformal current, which appears as the origin of the cosmological
constant. In consequence, it is no longer a free parameter, and can be
determined in terms of other quantities. When applied to the
propagation of ultra-high energy photons, de Sitter general relativity
gives a good estimate of the time delay observed in extragalactic
gamma-ray flares. It can, for this reason, be considered a new
approach to quantum gravity."

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/lajos.htm#a2

 

[kT]

On Dec 6, 12:04 pm, Uncle Al <Uncle...@hate.spam.net> wrote:
> http://arxiv.org/abs/0711.2274
>
> The cosmological constant is claimed to be tamed and computable.
> Curious...
>
> "The Poincare' group generalizes the Galilei group for high-velocity
> kinematics. The de Sitter group is here assumed to go one step
> further, generalizing Poincare' as the group governing high-energy
> kinematics. Algebraically, this is done by supplementing spacetime
> translations with proper conformal transformations. This change in
> special relativity implies concomitant changes in general relativity
> -- yielding a de Sitter general relativity. The source current turns
> out to include now, in addition to energy-momentum, the proper
> conformal current, which appears as the origin of the cosmological
> constant. In consequence, it is no longer a free parameter, and can be
> determined in terms of other quantities. When applied to the
> propagation of ultra-high energy photons, de Sitter general relativity
> gives a good estimate of the time delay observed in extragalactic
> gamma-ray flares. It can, for this reason, be considered a new
> approach to quantum gravity."[/color]

Whatever. Hey Al, this is for you. Check this out :

http://arxiv.org/abs/0712.0472

Recombination kinetics of a dense electron-hole plasma in strontium
titanate

A. Rubano, D. Paparo, F. Miletto Granozio, U. Scotti di Uccio, L.
Marrucci

We investigated the nanosecond-scale time decay of the blue-green
light emitted by nominally pure SrTiO$_3$ following the absorption of
an intense picosecond laser pulse generating a high density of
electron-hole pairs. Two independent components are identified in the
fluorescence signal that show a different dynamics with varying
excitation intensity, and which can be respectively modeled as a
bimolecular and unimolecolar process. An interpretation of the
observed recombination kinetics in terms of interacting electron and
hole polarons is proposed.

Can you say 'new experimental paradigm'? We've been doing something
like this with bismuth triiodide for decades. Non destructive UV
saturation, and then let the intrinsic electronic structure sort it
all out.

 

[Hontas F. Farmer]

Uncle Al wrote:

> http://arxiv.org/abs/0711.2274
>
> The cosmological constant is claimed to be tamed and computable.
> Curious...
>
> "The Poincare' group generalizes the Galilei group for high-velocity
> kinematics. The de Sitter group is here assumed to go one step
> further, generalizing Poincare' as the group governing high-energy
> kinematics. Algebraically, this is done by supplementing spacetime
> translations with proper conformal transformations. This change in
> special relativity implies concomitant changes in general relativity
> -- yielding a de Sitter general relativity. The source current turns
> out to include now, in addition to energy-momentum, the proper
> conformal current, which appears as the origin of the cosmological
> constant. In consequence, it is no longer a free parameter, and can be
> determined in terms of other quantities. When applied to the
> propagation of ultra-high energy photons, de Sitter general relativity
> gives a good estimate of the time delay observed in extragalactic
> gamma-ray flares. It can, for this reason, be considered a new
> approach to quantum gravity."
>[/color]

Cleaner...Not really. Consider the following statements.

"There is a crucial diference between ordinary (or Poincare) and de Sitter
special relativities. Ordinary special relativity is always restricted to
the (at) Minkowski spacetime. This means that ordinary special relativity
is essentially a kinematic theory in the sense that the gravitational
effects can always be neglected. When the de Sitter group is assumed to
govern the ultra high energy kinematics, however, spacetime cannot remain
at because the de Sitter symmetry requires a (curved) local de Sitter
spacetime."

Consider for a moment all of the quantum field theory and particle physics
we have done here on the surface of the earth. All of that was done in a
considerable gravitational field. Why is it that we can neglect the
effects of this field in our experiments and calculations and still get
precise results? We can do this because of the non local curvature of
space time. Each interaction between particles in a QFT occurs in a tiny
little region of space-time that is locally flat. That is why all the QFTs
we have which are formulated for flat space-time work so well.

If this theory is correct then in the ultra relativistic regime where the de
Sitter special relativity would take over we would have some very wrong
results. Because in QFT's formulated for curved space-times there are
virtual particles created and anihillated, the meaning of a vacuum state
becomes fuzzy, and a million other consequences. None of which have been
observed in any of our experiments which by their nature involve
interactions that are local.

--
""I am enough of an artist to draw freely upon my imagination. ..." A.
Einstein
http://www.geocities.com/hontasfx/theory.xhtml

 

[Hontas F. Farmer]

Uncle Al wrote:

> http://arxiv.org/abs/0711.2274
>
> The cosmological constant is claimed to be tamed and computable.
> Curious...
>
> "The Poincare' group generalizes the Galilei group for high-velocity
> kinematics. The de Sitter group is here assumed to go one step
> further, generalizing Poincare' as the group governing high-energy
> kinematics. Algebraically, this is done by supplementing spacetime
> translations with proper conformal transformations. This change in
> special relativity implies concomitant changes in general relativity
> -- yielding a de Sitter general relativity. The source current turns
> out to include now, in addition to energy-momentum, the proper
> conformal current, which appears as the origin of the cosmological
> constant. In consequence, it is no longer a free parameter, and can be
> determined in terms of other quantities. When applied to the
> propagation of ultra-high energy photons, de Sitter general relativity
> gives a good estimate of the time delay observed in extragalactic
> gamma-ray flares. It can, for this reason, be considered a new
> approach to quantum gravity."
>[/color]

Cleaner...Not really. Consider the following statements.

"There is a crucial diference between ordinary (or Poincare) and de Sitter
special relativities. Ordinary special relativity is always restricted to
the (at) Minkowski spacetime. This means that ordinary special relativity
is essentially a kinematic theory in the sense that the gravitational
effects can always be neglected. When the de Sitter group is assumed to
govern the ultra high energy kinematics, however, spacetime cannot remain
at because the de Sitter symmetry requires a (curved) local de Sitter
spacetime."

Consider for a moment all of the quantum field theory and particle physics
we have done here on the surface of the earth. All of that was done in a
considerable gravitational field. Why is it that we can neglect the
effects of this field in our experiments and calculations and still get
precise results? We can do this because of the non local curvature of
space time. Each interaction between particles in a QFT occurs in a tiny
little region of space-time that is locally flat. That is why all the QFTs
we have which are formulated for flat space-time work so well.

If this theory is correct then in the ultra relativistic regime where the de
Sitter special relativity would take over we would have some very wrong
results. Because in QFT's formulated for curved space-times there are
virtual particles created and anihillated, the meaning of a vacuum state
becomes fuzzy, and a million other consequences. None of which have been
observed in any of our experiments which by their nature involve
interactions that are local.

--
""I am enough of an artist to draw freely upon my imagination. ..." A.
Einstein
http://www.geocities.com/hontasfx/theory.xhtml

 

[Fall]

On Dec 6, 1:04 pm, Uncle Al <Uncle...@hate.spam.net> wrote:
> http://arxiv.org/abs/0711.2274
>
> The cosmological constant is claimed to be tamed and computable.
> Curious...
>
> "The Poincare' group generalizes the Galilei group for high-velocity
> kinematics. The de Sitter group is here assumed to go one step
> further, generalizing Poincare' as the group governing high-energy
> kinematics. Algebraically, this is done by supplementing spacetime
> translations with proper conformal transformations. This change in
> special relativity implies concomitant changes in general relativity
> -- yielding a de Sitter general relativity. The source current turns
> out to include now, in addition to energy-momentum, the proper
> conformal current, which appears as the origin of the cosmological
> constant. In consequence, it is no longer a free parameter, and can be
> determined in terms of other quantities. When applied to the
> propagation of ultra-high energy photons, de Sitter general relativity
> gives a good estimate of the time delay observed in extragalactic
> gamma-ray flares. It can, for this reason, be considered a new
> approach to quantum gravity."
>
> --
> Uncle Alhttp://www.mazepath.com/uncleal/
> (Toxic URL! Unsafe for children and most mammals)http://www.mazepath.com/uncleal/lajos.htm#a2[/color]

Uncle Al

I came across this;

http://xxx.lanl.gov/abs/astro-ph/0307311

"We present a new approach to constructing inflationary models in
closed universes. Conformal embedding of closed-universe models in a
de Sitter background suggests a quantisation condition on the
available conformal time. This condition implies that the universe is
closed at no greater than the 10% level. When a massive scalar field
is introduced to drive an inflationary phase this figure is reduced to
closure at nearer the 1% level. In order to enforce the constraint on
the available conformal time we need to consider conditions in the
universe before the onset of inflation. A formal series around the
initial singularity is constructed, which rests on a pair of
dimensionless, scale-invariant parameters. For physically-acceptable
models we find that both parameters are of order unity, so no fine
tuning is required, except in the mass of the scalar field. For
typical values of the input parameters we predict the observed values
of the cosmological parameters, including the magnitude of the
cosmological constant. The model produces a very good fit to the most
recent CMBR data. The primordial curvature spectrum predicts the low-l
fall-off in the CMB power spectrum observed by WMAP. The spectrum also
predicts a fall-off in the matter spectrum at high k, relative to a
power law. A further prediction of our model is a large tensor mode
component, with r~0.2."

Fall

 

[Fall]

On Dec 6, 1:04 pm, Uncle Al <Uncle...@hate.spam.net> wrote:
> http://arxiv.org/abs/0711.2274
>
> The cosmological constant is claimed to be tamed and computable.
> Curious...
>
> "The Poincare' group generalizes the Galilei group for high-velocity
> kinematics. The de Sitter group is here assumed to go one step
> further, generalizing Poincare' as the group governing high-energy
> kinematics. Algebraically, this is done by supplementing spacetime
> translations with proper conformal transformations. This change in
> special relativity implies concomitant changes in general relativity
> -- yielding a de Sitter general relativity. The source current turns
> out to include now, in addition to energy-momentum, the proper
> conformal current, which appears as the origin of the cosmological
> constant. In consequence, it is no longer a free parameter, and can be
> determined in terms of other quantities. When applied to the
> propagation of ultra-high energy photons, de Sitter general relativity
> gives a good estimate of the time delay observed in extragalactic
> gamma-ray flares. It can, for this reason, be considered a new
> approach to quantum gravity."
>
> --
> Uncle Alhttp://www.mazepath.com/uncleal/
> (Toxic URL! Unsafe for children and most mammals)http://www.mazepath.com/uncleal/lajos.htm#a2[/color]

Uncle Al

I came across this;

http://xxx.lanl.gov/abs/astro-ph/0307311

"We present a new approach to constructing inflationary models in
closed universes. Conformal embedding of closed-universe models in a
de Sitter background suggests a quantisation condition on the
available conformal time. This condition implies that the universe is
closed at no greater than the 10% level. When a massive scalar field
is introduced to drive an inflationary phase this figure is reduced to
closure at nearer the 1% level. In order to enforce the constraint on
the available conformal time we need to consider conditions in the
universe before the onset of inflation. A formal series around the
initial singularity is constructed, which rests on a pair of
dimensionless, scale-invariant parameters. For physically-acceptable
models we find that both parameters are of order unity, so no fine
tuning is required, except in the mass of the scalar field. For
typical values of the input parameters we predict the observed values
of the cosmological parameters, including the magnitude of the
cosmological constant. The model produces a very good fit to the most
recent CMBR data. The primordial curvature spectrum predicts the low-l
fall-off in the CMB power spectrum observed by WMAP. The spectrum also
predicts a fall-off in the matter spectrum at high k, relative to a
power law. A further prediction of our model is a large tensor mode
component, with r~0.2."

Fall